School Science Lessons
2024-03-13
Primary Science Lessons, Year 5
(year 5)
Contents
Suggested answers to the teacher's questions are shown within [square brackets].
5.26 Air pressure in all directions
5.15 Breathing in and out
5.43 Burn to make carbon
5.03 Coral, sea anemone
5.36 Cover crops
5.28 Seed depth
5.24 Describe clouds
5.33 Different rocks
5.20 Digestion of food
5.06 Fish life cycle
5.29.1 Germinate maize grain
5.27 Germination test
5.42 Heated air expands
5.12 Image with a lens
5.41 Keep water clean
5.31 Leaves lose water
5.10 Light travels in straight lines
5.25.5 Link spring balances
5.39 Make clay pots
5.11 Mirror reflects light
5.25.4 Paddle a canoe
5.25.3 Pile of coins
5.14 Pinhole camera
5.30 Plant roots absorb water
5.32 Protect mangroves
5.02 Protect sea animals
5.25 Push and pull forces
5.25.1 Push and pull carts
5.25.2 Push and pull a box
5.22 Rain gauge
5.37 Rain on slopes
5.01 Sea animals and plants
5.07 Sea food chains
5.04 Shellfish and snails
5.44 Soil fertilizer trial
5.34 Soil profiles
5.05 Starfish, sea urchin
5.09 Steam wheel
5.08 Water wheel
5.13 Water drop magnifier
5.21 Water finds its own level
5.23 Wind speed and direction
5.01 Sea animals and plants
See diagram 9.44: Ecklonia.
Teach the children to name many different plants and animals of the sea.
This lesson is designed to give children an appreciation of the great variety of plants and animals in the sea.
Do not teach the children the scientific classification in brackets over the page.
The children should list as many different types of plants and animals as possible by visiting the seashore, looking at pictures in books
and remembering their own experiences.
You cannot see microscopic animals, e.g. Protozoa or microscopic algae, but sometimes these plants and animals can change the
colour of the sea.
Bacteria are also microscopic and they cause dead plants and animals to rot.
Many large animals have a bony backbone made of a glassy substance called cartilage.
Porpoises, hippopotamuses and whales are not fish, they breathe air, have hair and suckle their young, so they are mammals.
Seaweed plants, e.g. Ecklonia, are large algae with no roots, stems, leaves or flowers, and they can be red, green or brown.
Tiny floating algae or animals are called plankton.
Sea grass grows on banks outside mangrove swamps.
It is an underwater flowering plant.
1. Give descriptions (characteristics) and name examples of different animals in the sea, e.g. soft sponges, corals sea anemones are
like flowers, tiny, long and soft worms, animals with jointed legs (shrimps), shellfish (molluscs), spiny skins (starfish and sea urchins),
have backbones and skeletons (vertebrates), plants (seaweed, sea grass).
Show pictures or specimens.
How many different kinds of plants or animals do you know?
Draw one specimen of each kind of animal or plant.
2. Collection of dead specimens in dilute formalin solution or methylated spirit, do not kill any animals for your collection.
Animals and plants in the rivers and sea
1. Microscopic single celled animals [Protozoa]
2. Sponges (dead sponge skeletons found on beaches) [Porifera]
3. Corals, sea anemone, jellyfish [Coelenterates ]
4. Flatworms, under rocks in shallow pools [Platyhelminthes]
5. Roundworms, mainly parasites [Nematoda]
6. Beach worms, bristle worm, tube worm [Annelid]
7. Mosquito, diving beetle, cockroach [Insecta]
8. Shrimps, prawns, crayfish, crabs, barnacles [Crustacean]
9. Chitons, cowrie, cone shell, turban shell, ear shell, volute, helmet shell, sea slug, oyster, clam, mussel, squid, octopus [Molluscs]
10. Starfish, brittle star, sea urchin, beche-de-mer [Echinodermata]
11. Shark, sting ray [cartilaginous fish] and Perch, eel, sea horse [bony fish]
12. Frog, toad [Amphibia]
13. Snake, turtle, crocodile [Reptile]
14. Sea gull, tern, frigate bird [Aves]
15. Hippopotamus, porpoise, whale [Mammalia]
16. Plants in the rivers and sea, Green, red and brown seaweed [Algae]
Ferns [Pteridophyta]
Raphia palm, sago palm [Gymnosperms]
Mangroves, rushes, grasses [Angiosperms]
Bacteria and fungi (cause rotting)
5.02 Protect sea animals
See diagram 9.307: Turtle
Teach the children to explain why we should treat sea animals as a renewable resource.
Use conservation campaign posters for a particular country.
Before this lesson, think of some local examples of loss of natural resources, e.g. inshore fish.
1. Explain the meaning of the word "resource" to the children.
It means something you can use when you need it.
A forest is a resource for fuel wood.
A river is a resource for stones, clay and minerals such as gold.
2. If a resource can keep producing something that you need, you say it is a renewable resource.
A forest is a resource for fuel wood for many years provided you do not cut down all the trees.
Stones, clay and minerals are not renewable, once you take them away they are gone.
Living resources are renewable, a garden is a living resource that can produce food year after year.
3. Non-living resources are not renewable.
Living resources are renewable only if some of it is used and the rest left to grow and reproduce.
4. The animals in the sea are one of your greatest living resources. For a long time in the past people have eaten only some animals
and let the rest grow and reproduce.
The animals have remained a renewable resource.
5. Nowadays people catch too many sea animals.
If you catch too many animals such as fish, porpoise and crab there may not be enough left to renew the resource.
Take just enough for your needs, but let most sea animals grow and reproduce.
Otherwise they will become a non-renewable resource and die out.
This will be a great loss to future generations in your country.
Recent government efforts in many countries focus on campaigns through various establishments and institutions to do and ensure
systematic conservation of natural resources.
5.03 Coral, sea anemone
See diagram 9.305: Shells
Teach the children to identify these animals and explain that these animals all have the same basic structure.
Use different coral specimens and pictures or specimens of sea anemones and jellyfish.
You can teach this lesson on a coral reef or in the classroom.
1. If you have seen pieces of coral and a coral reef.
Explain that coral is made up of many tiny animals each of which has a coat of hard lime.
The lime coats stick together to make the pieces of coral and the coral reef.
The coral animals die leaving the dead coral made of lime.
Show pieces of coral.
Is it alive? [No.]
Where did the coral animals live? [In the holes in the dead coral.]
Can you name different kinds of coral? The coral animals are so small you cannot study them.
2. However, sea anemones are much larger, have soft bodies and are similar to coral animals.
The sea anemone has three main parts:
2.1 tentacles that can catch food,
2.2 mouth,
2.3 stomach.
Tentacles can kill small fish by stinging them with poison.
Can you put a finger in a sea anemone's mouth?
Sea anemones are called the "flowers of the reef", because they have bright colours.
Sea anemones live in rock pools and catch animals with their tentacles. Sometimes they pick up shells so they can hide.
Sometimes there is a friendly fish that swims among the tentacles and does not get stung.
3. A jellyfish does not look like a sea anemone or coral animal, but it does have the same three parts: tentacles, mouth and stomach.
4. Look at the drawing of the coral animal cut open.
Turn it upside down.
Imagine the soft body swelled up with jelly.
Now you have a jellyfish.
Jellyfish float in the sea.
Jellyfish can sting fish with their tentacles then eat them.
Jellyfish can sting people.
Some of them glow at night.
They swim very slowly.
5.04 Shellfish and snails
See diagram 9.305: Shells
Teach the children to describe and name different kinds of molluscs, shellfish and land snails.
Use examples of molluscs, shellfish and land snails.
Collect different kinds of shells or shellfish and land snails.
You can also prepare the class for an excursion to the coral reef.
A live land snail or a shellfish in a jar of sea water will interest the children.
Little land snails (Limocolaria) can be collected at night or early in the morning.
Shellfish are called Molluscs.
1. If you know an animal that has a soft body and carries its house on its back. [A land snail or sea snail.]
Explain that their body is divided into three parts: head, foot and coiled stomach.
The head has a mouth and eyes at the end of tentacles.
The body can be pulled into a coiled shell.
Sometimes the house has a door made of hard shell.
Molluscs can move along using their big foot.
2. Snails are one kind of animal called molluscs.
There are four different kinds of molluscs:
2.1 Snails, have a single coiled shell, e.g. land snails, cowries, ear shells, cone shells, auger shells, helmet shell, volute, baler shell.
Some have lost their shell, e.g. land slugs and sea slugs.
2.2 Chitons have flat plates instead of a shell, a small head and a big foot.
2.3 Bivalves have two flat shells joined by a muscle that can close them together, like clapping hands.
Some can use the foot to burrow in the sand, e.g. scallop, cockle and muscle.
Others are fixed in one place, e.g. oyster, clam.
2.4 A squid and octopus foot is divided into eight arms.
Squids can swim by squirting water out backwards.
The squid has a small internal shell and the octopus has no shell.
How many kinds of molluscs can you find?
Make a shell collection and name the types of shells from different localities.
5.4.1 Shellfish, molluscs
Teach the children to classify shells into groups based on observed similarities and differences.
Collect different types of shells and tell the children to bring some.
1. Give each group a pile of mixed shells.
2. Sort the shells into small groups.
You must say why you put shells into a particular group.
Do not tell the children how to do it.
Let the children decide their own groupings.
3. Pick out one shell from a group.
Why did you put it into that group? [Some possible answers: the shells look the same, and have the same colour, same shape, same
markings.]
4. Do you know the common name for each group? [Some examples include scallop, top shell, cone shell, snail shell, cowrie, clam.]
5. Arrange the shells in each group in order of size.
6. Draw the medium-sized shell of each group in your book.
7. Make a collection of shells for the class.
Label the shells with common names.
5.4.2 Shellfish, molluscs
Teach the children to explain why we should protect shellfish.
Shellfish are molluscs.
Molluscs have a body divided into three parts: head, a large foot, and coiled stomach in a shell.
Explain that shellfish are interesting animals that are part of the natural heritage.
If shellfish are all killed, because more people are eating them or selling the shells, then something that you all own would be lost.
Some shellfish appear on postage stamps: Cowrie, Trochus, Glory-of-the-Sea, Bailer Shell, Pearly Nautilus, Conch, Triton.
Shellfish are valuable for four reasons:
1.1 Shellfish are part of the food web, plants and animals depend on each other for food and shelter.
These plants and animals have lived in the local natural environment for a long time, because there is a balance of numbers.
If we kill too many of one kind of plant or animal, you upset the balance and other plants and animals will be affected.
1.2 Shellfish are a source of valuable growth food.
Yet the human population is increasing rapidly and some kinds of shellfish on the coast could all be eaten.
1.3 Shellfish are a source of money.
Some shells such as Cowrie, Trochus and Glory-of-the-Sea can be sold to overseas buyers.
Also, tourists like to buy shells to remember the country they have visited.
1.4 Shellfish are a part of our natural environment for all people to look at and enjoy.
These shellfish are part of your culture and history.
Ancestors were famous for the inlay work in carvings using Pearly Nautilus shell.
If all these shellfish were killed this traditional art work would be lost.
Before the lesson, tell the children to bring some shells.
1. Show the children the shells and pictures of shells.
Do people eat them? [Yes.]
Do people use them? [Yes, e.g. Baler Shell.]
Do people sell them? [Yes, to tourists.]
Do people make anything with them? [Yes, Mother-of-pearl inlay work for traditional decoration and to sell to tourists.]
2. Explain how shells are part of your natural heritage.
Shells are something our ancestors owned, something you own, and something that should be still living for your children.
3. Explain why shellfish are valuable for the:
* food web,
* food,
* money in culture.
4. Explain why shellfish could all be killed:
* There are more people now than before,
* there are more canoes with outboard motors and people with diving equipment,
* there are more people want to sell shells,
* there are more foreign boats and tourists.
5. Explain how children can protect shellfish:
5.1 Tell people about the importance and the danger of killing too many shellfish.
5.2 Tell children to watch foreign boat crews and tourists.
5.3 Not to kill the shellfish unless very hungry.
6. Display of shells under the heading "Our Natural Heritage"
5.05 Starfish, sea urchin
See diagram 9.304: Echinoderms
Teach the children to identify and list the different types of echinoderms.
Use drawings and preserved specimens of types of echinoderms.
The spiny skinned animals, called echinoderms are found only in the sea.
Echinoderms have a circular design.
If you cut through the centre of their mouth in any direction the two halves look the same.
Beside having spines in their skins or spines sticking out, echinoderms have hundreds of little tube feet to help them move along the
bottom of the sea.
The starfish usually has five arms and a mouth facing down.
Starfish can suck on to the shell of a bivalve mollusc such as an oyster, pull open the shells then eat the inside.
Brittle stars have a separate round body and long legs that they can drop off when they are frightened.
Sea urchins are globe shaped, have long spines and downwards facing teeth that can grind a hole in a shellfish.
Beche-de-mer is an example of the sea cucumbers that have lost their spines.
When frightened, beche-de-mer they spit out their stomach.
Beche-de-mer or trepang is exported overseas for Chinese soup.
Use specimens or pictures of these animals.
The following groups of spiny skinned animals are called Echinoderms:
1.1 Starfish,
1.2 Brittle stars,
1.3 Sea urchins,
1.4 Sea cucumbers, e.g. beche-de-mer.
1.5 Feather stars
1. Show drawings or specimens of these animals.
What are their common features? [Shape, spiny skins, live on the sea bottom.]
2. Look at the starfish.
Does it have a front or back? [No.]
Are the arms different? [No.]
How does it move? [With its tube feet.]
What are the arms for? [To pull apart the shells of shellfish.]
3. Draw each different kind.
The aim is to perfect observation and creativity in them.
4. Make a collection of dead echinoderms, but do not kill any animals on the reef.
5.06 Fish life cycle
See diagram 9.301: Life cycle of a fish
See diagram 9.302: Shark, Bony fish
Teach the children to explain the life cycle of a bony fish.
Use illustrations of the life cycle of a fish.
Bring some freshwater fish to class.
25.0 Class Chondrichthyes (sharks, dogfish, stingrays, rays, cartilaginous fish, elasmobranchs)
26.0 Class Osteichthyes, bony fish (Class Actinopterygii, ray-finned fish)
Sharks, dogfish and stingrays do not have a skeleton made of bones.
Their skeleton is made of a clear substance that can bend easily called cartilage.
So sharks and stingrays are called cartilaginous fish.
Most fish have hard bones so they are called bony fish.
Show the diagrams of the life cycle of a fish to explain the following points:
1. A female fish lays eggs in the water and a male fish puts many sperm into the water near the eggs.
2. Many eggs are not fertilized.
3. Only those that are fertilized become little fish.
4. Many little fish are eaten, so only a few grow into adult fish.
5. The female fish must lay thousands of eggs if some are to grow into adult fish.
6. Examine closely the adult fish.
Can you see any differences between the male and female fish?
Can you draw the differences?
5.07 Sea food chains
Teach the children to explain the importance of keeping the food chains in the sea unbroken.
Use plants and animals in the environment and in the sea.
Children should understand that all plants and animals in the sea are important because they are related by food chains.
Plants and animals depend on each other for food.
Also, when plants and animals die their bodies are rotted by bacteria to be used by simple plants and animals again.
You can think of the food chains usually or by particular examples.
An example of a food chain is seaweed is eaten by a shellfish is eaten by a fish is eaten by a bird.
Seaweed --> Shellfish --> Fish --> Bird.
When each of these animals dies, the material in their bodies decomposes and can be used by the seaweed again.
However, if you eat all the shellfish or fish then the food chain is broken.
Usually plants are eaten by animals are eaten by larger animals are eaten by larger animals.
If ">>" means "is eaten by", you can show a food chain as: plants >> small fish >> big fish >> shark >> man
If we kill all the animals or plants in any step of the food chain then the food chain is broken and all the living things in the food chain
are affected.
1. Give examples of living things in the sea eating other living things, e.g. smaller fish eaten by sharks.
Write all the examples on the chalk board.
So far you have steps in the food chain, tell the children to tell you a third or fourth step, e.g. seaweed, fish, shark, man.
2. Can you make different food chains?
Can you make food chains with many steps?
Try this with the children and write the steps on the chalk board.
3. What is passed along the food chain? [The material in the bodies of the plant and animals.]
What happens to the materials when the plants or animals die and are not eaten? [They rot.]
Is the material of their bodies lost from the food chain? [No, simple plants and animals can use it again.]
4. Show the general food chain.
Plants fish one fish two shark
5. The dotted lines show the bodies of dead plants and animals made rotten by bacteria then used by plants again.
What would happen if you caught all the fish? [There would be no food for fish two and later no food for the sharks.
The food chain would be broken.]
6. Name any kinds of animals or plants in the sea that could be wiped out by too much fishing or hunting.
How many animals of the sea should you catch? [Catch some, but do not catch so many to break the food chain.]
7. Discussion with an old fisherman or fisheries officer on whether there are as many fish now as before.
Are some food chains already broken? Visits to agricultural departments (fishery section) can help us to find out more about this.
5.08 Water wheel
See diagram 9.2.1: Water wheel
See diagram 4.199: Overshot water wheel
A water wheel is a source of hydroelectric power.
Teach the children to make a water wheel and show how moving water can turn a wheel.
Use water, hose, or water in a bucket.
The wheel can be made in any of the following ways:
1.1 Use thin bamboo, with thin pieces of tin or cardboard for the blades and a smooth stick for an axle.
1.2 Use pawpaw stalks instead of bamboo with a smooth stick for an axle.
1.3 Cut a small square of coconut husk.
Make a hole in the middle with a hot nail.
Push the pieces of tin in the sides.
Let it spin on the nail or a smooth stick.
1.4 Cut a round piece of paper or taro stem.
Stick very stiff leaves round the edge.
Spin on a smooth stick.
1.5 Stick Plasticine (modelling clay) around a piece of bamboo.
Stick cardboard or tin pieces in the Plasticine.
Spin on a smooth stick.
1.6 Use an empty cotton reel and tin sheets.
Spin on a nail.
1. Give out the materials and show how to make their water wheels.
2. Put the wheel in running water under a tap or by pouring water over it.
What happens? [The wheel turns when the water hits the blades.]
Increase the speed of the water.
What happens to the water wheel? [It turns faster.]
3. What happens when the wheel is placed in running water. [It turns or spins.]
What happens if you increase the speed of the water? [The wheel turns faster.]
How can you increase the speed of the water? [By opening the tap more, by making the water fall further.]
4. Collect the water wheels and keep them for the lesson on Steam Wheels.
5. Water wheels are used to generate hydroelectricity.
the electrical generator is often placed at the bottom of a water fall and water is lead to it in a pipe from the top of the waterfall.
5.09 Steam wheel
See diagram 9.2.1: Steam wheel
Teach the children to show that steam can turn wheels.
Use water wheels from previous lesson on water wheels.
Cans with tight fitting lids with a small hole in the lid.
Burners, heating stand and water. Make the holes in the tin lids with a nail.
Do not put too much water in the tin as it will take too long to boil and produce steam.
About four cm should be enough.
1. Give out the materials and tell the children to pour water into the can and then fit the lid on tightly.
Place the can of water on a heating stand.
Light the burner and heat the water.
2. When the water is boiling tell the children what is coming out of the hole in the tin lid. [Steam.]
3. Take it in turns to hold your water wheel over the hole in the lid as shown in the diagram.
4. What happens? [The wheel turns.]
5. What is formed when water boils? [Steam.]
What causes the wheel to turn? [Steam.]
Which can turn a wheel faster, water or steam? [Steam.]
6. The wheels of a steam engine are turned by steam.
Steam engines are used to make electricity, drive trains and boats.
Wood or coal is burnt to heat water to produce the steam.
Steam boats and trains are not common now.
However, in many countries most of the electricity is made from burning coal in steam engines that turn on electric generators.
7. Draw pictures of steam engines used in boats, trains and power stations.
5.10 Light travels in straight lines
See diagram: 28.105.1: Light travels in straight lines
Teach the children to show that light travels in straight lines.
Use 3 pieces of cardboard about 25 cm × 25 cm for each group, candles or a torch or a mirror to reflect sunlight, jar of water,
chalk dust, piece of string, rubber tubing or pawpaw petiole about 50 cm long.
Light is invisible, it cannot be seen.
Completely transparent substances, like air it also cannot be seen, because you allow all light to pass through them.
You cannot see light passing through air or water unless the air or water has something in it, e.g. chalk dust, street dust that will
reflect the light into your eyes
1. Use a pin to cut a hole in three pieces of cardboard.
Hold each piece of cardboard about 10 cm apart.
Thread a piece of string through the holes and pull very tight.
Place a candle in line with the string. Take away the string and tell the children to look through the hole at the candle.
2. Can you see the candle? [Yes.]
What would a line from your eye through the holes to the candle look like? [A straight line.]
3. Move one piece of cardboard.
Can you see the candle? [No.]
Why not?
4. Put some chalk dust in a jar of water.
Shine some light through it.
How does the light travel? [In a straight line.]
Can light bend? [No.]
Can light go around corners? [No.]
5. You see around corners with a mirror, but the light still travels in straight lines.
5.11 Mirror reflects light
See diagram 28.2.2: Reflection in a plane mirror
See diagram 28.2.13: Reflection of a clock in two mirrors
See diagram 5.11: Two mirrors
Teach the children to show how light travels when it is reflected by a mirror.
Use mirrors, cardboard and scissors, shiny surfaces, e.g. aluminium foil, tin lids, rubber ball.
Practice before the lesson with the recommended materials.
1. Give out two mirrors and different shiny surfaces to each group.
2. Use a mirror and shiny surfaces to reflect a beam of sunlight along the floor, or the ground or along the top of a desk.
Which things reflect the light best? [Materials with smooth shiny surfaces.]
3. Use scissors to cut a slot out of your piece of cardboard, to put the slot over the beam of light.
4. Turn the second mirror to reflect the thin beam of light to the left, to the right, up and down.
5. Tell one child to stand against a wall holding the second mirror to the chest.
Another child should reflect light on to the second mirror from the first mirror.
A third child can then see the reflected light.
Tell another child to throw a rubber ball from the first mirror at the wall behind the second mirror.
Where does the ball go? [It bounces off the wall in the same direction as the light.]
Reflection occurs when light bounces off shiny surfaces.
6. Place two mirrors at right angles and a bottle top between.
How many reflections are there?
5.12 Image with a lens
See diagram: 28.1.1.5: Image with a lens
Teach the children to form an image on a screen using a lens and can describe the image and measure its distance from the lens.
Use candles or flame, white paper for screens, you can rub some cooking oil on the paper to make a better screen, magnifiers.
Darken part of the classroom.
Formation of images on screens and distance measurement are the real focus of this lesson.
1. Put the candle, lens and screen in a darkened area so that the image of a candle can be seen on the screen.
Place the lens at 10 cm from the screen to get the sharpest image.
2. Describe the image. [Small and upside down.]
What happens when you move the lens closer to the candle? [The image gets larger and is still upside down.]
When is the size of the image is about equal to the size of the candle flame? [When the lens is about half way between the screen and
the candle.]
3. Look at images of objects outside the classroom.
Describe them. [The images are smaller than the objects and they are upside down.]
4. Lenses are found in eye glasses, cameras, binoculars, projectors.
5. Where is the screen in your eye? [The screen is at the back of the eye, the lens is at the front of the eye where light enters.
So in your eye the distance between the screen and the lens stays the same.]
5.13 Water drop magnifier
See diagram 28.1.17: Water lens
Teach the children to make a water drop microscope and use it to describe the structure of small objects.
You need a piece of cardboard and a piece of sticky tape.
Punch a hole through the sticky tape and the cardboard.
Put a drop of water on the hole to make a water drop microscope.
To use the microscope attach it to a ruler at with sticky tape, put some hair or a leaf on the paper, look down through the water drop
and move the pencil between the book and paper.
1. Show the curved surfaces of their magnifying lenses.
[Glass with a curved surface can magnify, make things bigger.]
We can make a curved shape out of water, a kind of lens.
2. Show how to make the water drop microscope.
Show how to set up the water drop microscope.
Look at the shape of the drop very carefully.
3. Put a small printed word under the water drop microscope, e.g. CAT.
Write this word at the size you see it.
4. Move the microscope up and down.
Focus it until the printed letters look bigger.
The children may have to remove a little water from the drop with their fingers until the printed letters look bigger.
5. Put a little bit of sugar on their paper.
Spread the sugar under the microscope and then observe it.
6. Look at different things using your microscope, e.g. soil, ants, roots, feathers.
5.14 Pinhole camera
See diagram: 28.105.2: Pinhole camera
Teach the children to make a pinhole camera.
The pinhole camera is just a light proof box using a pinhole about 0.5 mm in the centre of one side instead of a lens.
The opposite side of the box can be a translucent screen or photographic film that can be exposed.
Some modern photographers use the pinhole camera to obtain its unique soft images and distortions in perspective.
These images the human eye would never see.
The pinhole camera is similar to the "camera obscura".
Teach the children to make a pinhole camera and describe the difference between the image and the object.
Use paper screen, nearby objects.
Make a pinhole camera before the lesson.
An image is the picture of an object on a screen.
The image of a pinhole camera on a screen is upside down.
1. Show your pinhole camera.
2. Make a small hole in the bottom of the tin using a nail.
Cover the open end of the tin with a piece of thin paper, e.g. typing, tracing or greased paper.
This is the screen on which the picture will be formed.
Use a rubber band or a piece of string to hold the paper on the tin.
Tie a piece of newspaper around the tin to form a tube.
This makes the screen dark.
The picture is easier to see in the dark.
3. When the children have made their pinhole cameras tell the children to point them towards the door or windows.
Let the children look at trees, buildings through their pinhole cameras.
4. This is how a real camera works except that the paper screen is the film covered with light sensitive substances.
5. Measure height of object / height of image, and distance from object to pinhole / distance from pinhole to screen.
6. The first camera designed for use by children was a box camera manufactured by KODAK in 1900 called a "Brownie".
5.15 Breathing in and out
See diagram 9.242.2: Lungs
See diagram 9.242.1: Simulated diaphragm
Use a watch with a second hand, bucket with a handle.
The following lessons are designed with two aims:
To give children experience in observing their breathing mechanism and
to improve observation of their own bodies.
1. Tell the children to sit quietly watching you.
What are you doing? [Nothing. we are just sitting still. We are not doing anything].
You are sitting still, but you are also breathing in and out.
Did you realize you were breathing? [No.]
What made you breathe in and out? [It just happens.]
Your brain makes you breathe in and out.
You don't have to think about it.
It is automatic.
2. The children sit quietly watching you.
Tell the children that you will count to 100, using the seconds hand of a watch.
Tell the children to close their mouths, hold their noses and stop breathing.
Then they can start breathing again.
Give the order and start counting.
Why did YOU not wait until the count of 100? [We had to breathe again before you counted to 100.]
What made you breathe again? [The brain.]
3. Tell the children to breathe in and out very deeply 20 times.
Then say "Stop" and start counting to 100.
How long can you hold your breath now?
[About one minute.]
Why can you hold your breath longer?
your body needs oxygen gas.
If you breathe in deeply, your body stores some oxygen gas in the lungs so you can hold your breath longer.
4. Push one finger up under the lowest right rib.
Breathe deeply in and out.
What happens to their ribs when you breathe in? [They rise.]
Show the bucket.
If your rib is like the handle of the bucket, when you breath in it is like raising the handle of the bucket.
When you breathe out, the handle of the bucket goes down.
Feel up under your ribs again and breathe in deeply.
What happens to your finger when you breathe in? [It is pushed down.]
What pushes it down?
Explain that a big muscle called the diaphragm pushes the finger down.
If you run a long way, you may get a pain in your diaphragm called a "stitch".
5. Does your the chest gets bigger or smaller when you breathe in? [Bigger, the chest expands.]
What part of the chest moves? [Two parts, the ribs turn up like a bucket handle and the diaphragm pushes down.]
When you breathe in where does the air go? [It goes into the lungs.]
Where are the lungs? [There is one lung in each side of the chest.]
6. Why do you breathe in air? [Our body needs oxygen gas.]
At the start of the lesson, why were you breathing quietly? [We do not need much oxygen when sitting quietly.]
What happens to your breathing when you start running? [We breathe more quickly and deeply.]
Why do you breathe more when you are running? [Our body needs more oxygen gas.]
7. Sentence Completion:
You breath in, because your body needs [oxygen] gas.
Your body gets oxygen gas from [the air]
when you are sleeping or sitting quietly, do you breathe quickly or slowly?
We breathe slowly, because we do not need so much [oxygen gas].
When you are running, do you breathe quickly or slowly?
We breathe quickly, because we need much more [oxygen gas].
8.Breathe in and out rapidly through your nose and then through your mouth.
What do you notice? [The nose warms the air before you breathe it in.]
Close your mouth and hold your nose then try to breathe out.
What do you notice?
[We feel pressure inside the ear.]
This pressure is caused by the air pressing against skin in the ear called ear drums.
If you swallow, the pain will go away.
You may feel this pressure when you are in a landing aircraft and it makes babies cry.
5.20 Digestion of food
Teach the children to observe and discuss what happens during digestion by examining an animal's stomach.
Use food, chicken or rat, scissors and knife, chloroform solution and lens.
Recall the methods of studying internal organs of animals by means of dissection.
1. Digestion of food is in two stages:
1.1 Breakdown of food into smaller parts using teeth and tongue in the mouth,
1.2 Softening of the food by saliva in the mouth and acid in the stomach.
2. Let the children bite a dry biscuit, their teeth and tongue break it into smaller pieces, after a short time it tastes sweet, because the
saliva changes starch into sugar.
How many dry biscuits can you eat?
Nobody can eat more than two dry and salty "SAO" biscuits, because, after eating two biscuits, the saliva is used up.
3. Kill a chicken or toad and show the children the stomach.
Use the solution of chloroform.
It is like a bag made of hard muscle.
This muscle can mix the food with acid.
4. Cut open the stomach with scissors.
Turn the stomach inside out and show the children the digested contents.
5. Wash out the inside of the stomach and let the children examine it with a hand lens.
Can you see the folds in the walls?
6. Show the children the inside of a cow's stomach called tripe.
You can buy this in a butcher's shop or get it from a cow killed in a local ceremony.
Compare the size with the stomach of a rat or rabbit.
5.21 Water finds its own level
See diagram 12.0.0: Water finds its own level
Teach the children to show that the surface of water is always horizontal.
Use plastic tubing, ruler or metric stick, hose, water.
The depth of liquid in a vessel remains the same and does not depend on the shape of the vessel containing it.
1. Give out empty plastic tubes, water and rulers.
Pour some water above the desk in each arm.
What the difference is in height? [No difference.]
Pour some more water in and measure again.
What is the difference? [No difference.]
Draw a tube showing the level of the water and the horizontal line joining the level.
2. Hold one arm of the tube vertical then move the other arm apart keeping it vertical.
What happens to the height of the water in each arm? [It drops a bit.]
Compare the height of the water in each arm. [The heights are the same.]
3. Keep one arm of the tube steady, then bend down the other arm.
What happens to the height of water in each arm? [The height drops the same in each arm of the tube.]
4. Put your finger over the left hand end of the tube.
Then bend down the right hand end.
What happens to the water level? [It goes down as you bend the tube.]
What happens to the water level in the left hand tube? [It does not change.]
Are the levels still the same? [No.]
Why not? [The finger in the left hand end blocked the tube so no air can get in or out.]
5. Go outside on a slope.
How you can find two places at the same level? [Use two rulers and the hose or long plastic tube.]
B is five cm lower than A.
A is five cm higher than B.
[If the height of water in the tube is 10 cm at A and B, what is the difference in height at A and B? [The same height.]
If the height of water at A is 10 cm and at B is 15 cm, what is the height at A and B? [B is five cm lower than A.]
If the height of the water at A is 10 cm and at B is five cm, what is the height at A and B? [B is five cm higher than A.]
6. Using this tube, you can mark a horizontal line around a hill or along a slope.
This line is called a contour.
Mark a contour line along a slope.
7. Make contour banks to prevent soil erosion.
Mark a contour line along a slope or around a hill.
Dig a drain at the same depth along the contour line and use the soil to make a contour bank on the down side.
Pour some water in the contour ditch.
It should not flow along, because the bottom of the ditch should be horizontal.
The water should just spread out.
Contour ditches and banks can stop soil being washed down by the rain.
You can stop soil erosion.
If the height of the stick at A is three metres and at B is 1. 5 m, how does the ground slope from B to A? [B is 1. 5 m above A.]
5.22 Rain gauge
See diagram: 24.4.5: Rain gauge
Teach the children to read a rain gauge and record the rainfall each day.
Use a rain gauge, glass jar, rain chart
Table of average rainfall in two places: Honiara and Avu Avu
Month Honiara Avu Avu
January 249 262
February 234 225
Total Rainfall 2195 5787
Number of wet days 195 222
The site selected for a rain gauge should be level ground not near fences or trees.
Attach the bracket to a post about 1.5 metres above ground in a vertical position.
Rainfall should be measured at 9.00 a.m. daily and the amount entered on the rain chart against the date of the previous day.
To read the gauge, remove the plastic gauge from the bracket, take it to the chart, read the scale to the nearest millimetre (mm) and
record this on the chart, read the scale again and pour out the water.
Replace the scale in the bracket.
If you do not have a rain gauge, use a glass jar on a post.
Measure the depth of water in mm.
This reading in mm will not be the same as a proper rain gauge in mm.
Use a rain gauge or glass jar, rain chart on the wall (see over) or special rain recording book, ruled as in rain chart.
Each child must read the rain gauge.
1. Show the rain gauge or jar and ruler.
Show how to read the gauge with water in it:
1.1 Hold the top of the gauge vertically between thumb and first finger,
1.2 The level of water should be opposite the eye,
1.3 Keep their back straight and read level of water, to the nearest mm.
2. Read the gauge, but do not tell the children the reading.
Pass it from child to child.
Ask them to read the gauge and write down the reading.
When you have finished, ask each child to tell the class their readings.
3. Show the rain chart.
Show how to write in it.
4. Go outside to the rain gauge position.
Is it near trees or buildings? [No.]
Show how to read the rain gauge at 9.00 a.m. each day and record it on the rain chart.
5. Draw up a roster of children to read the rain gauge each day, two children each day.
6. Ask the children if they have heard rainfall measurements announced on the radio.
If used properly, the rain gauge method is the same as that used by government officers who measure rain.
Rain chart mm Jan.
 mm Feb.
 mm Mar.
 mm Apr.
 mm May.
 mm Jun.
 mm
Jul.
 mm Aug.
 mm Sept.
 mm Oct.
 mm Nov.
 mm Dec.
22 . . . . . . . . . . . .
23 . . . . . . . . . . . .
Totals . . . . . . . . . . . .
No.
days		 . . . . . . . . . . . .
Totals since 1 Jan 2 months 3 months 4 months 5 months 6 months 7 months 8 months 9 months 10 months 11 months 12 months
7. Record the readings from the chart on to a bar graph.
5.23 Wind speed and direction
See diagram 37.107: Wind vane
See diagram 37.108: Wind speed indicator, rotation anemometer
Teach the children to make regular recordings of wind speed and direction, and then summarize the observations.
Use a compass directions, a direction chart.
Give children the experience of making regular observations of the natural environment using inexact measurements of the wind.
Use to set out the compass directions in the playground and make a wind speed and direction chart for the wall.
Wind speed and direction chart, Place: Brisbane, Month: January, Time: 9.00, a.m., Date: 23/01/2018
Wind speed: calm, light, moderate, strong, very strong, total,
Wind direction: e.g. N north = 3, NE northeast = 0, E east = 0, SE southeast = 2, S south = 16, 16 SW south-west = 10,
W west = 0, NW northwest = 0,
Add the Totals vertically and horizontally to check for errors = 31
Wind speed Calm Light Moderate Strong Very Strong Total
Direction .
 .
 .
 .
 .
 .
N 3 . . . . 3
NE . . . . . .
E . . . . . .
SE . 1 1 . . 2
S . 8 7 1 . 16
SW . 5 5 . . 10
W . . . . . .
NW . . . . . .
Total 3 14 13 1 nil 31
Wind speeds Description of what you see and feel
Calm Smoke rises straight up, no wind at all
Light You can feel wind on your face, leaves move on the trees
Moderate Raise dust and paper, small branches move on the trees
Strong Trees sway, whistling sound in telegraph wires
Very Strong Twigs break off the trees, you find it hard to walk against the wind
Teach the children to estimate wind speed and directions.
1. Explain that it is important to know the pattern of wind speed and direction so people can predict the weather.
For example in January perhaps you can expect light to moderate winds coming from the south or south-west.
This information helps us to understand the weather and is useful for aircraft pilots and captains of ships.
2. Direction game:
Line the children facing north.
Hold your arms horizontally pointing your fingers.
Pretend this is the direction of the wind.
What is the direction of the wind? [Southerly.]
Turn around facing south and hold your arms up.
What direction is the wind? [North.]
Call out different wind directions.
The children have to point their arms in the wind direction.
East wind, point west, west wind, point east, south-west wind, point northwest, north west wind, point south east.
3. Wind Speed Game:
4. Describe the present wind speed and direction and record it on the chart.
Divide the class into pairs.
At 9.00 a.m. each day each pair has to record wind speed and directions.
5. What happens when a cyclone comes? [Strong wind in one direction, then calm, then strong wind in opposite direction.]
6. Beside the 9.00 a.m. reading observe wind speed and direction at 3.00 p.m.
Is there a pattern of difference between the 9.00 a.m. and 3.00 p.m. observations?
For example, perhaps in January the afternoon winds are usually lighter than the morning winds and swing from between S and SW
to between N and NE.
A similar observation and exercise should be done in your own area of the country.
7. Trade winds are winds that blow regularly in one direction, sometimes for six months, and are used for trade by sailing vessels.
In the Northern hemisphere winds blow from the north east and in the Southern hemisphere winds blow from the south east, about 30o
each side of the equator.
5.24 Describe clouds
See diagram 37.143: Clouds, altocumulus, cumulus
See diagram 37.135: Cloud in a bottle
See diagram 37.144: Stratocumulus
Teach the children to identify and describe different types of cloud and relate the children to rainfall.
Use a clean dry glass, clouds.
There are three main types of clouds, cumulus, stratus and cirrus.
1.1 Cumulus are the separate woolly clouds with sharp outlines.
Cumulus clouds join to form a big cloud with a flat dark base and bulging upper part, like a cauliflower.
It may rise high in the sky and then spread out to form an anvil cloud.
This cloud has a dark base and makes lightning, thunder and heavy rain.
1.2 Stratus is a great misty mass of cloud.
It has no sharp outline. Therefore, stratus clouds have no shape.
Lots of cumulus clouds can join to make a stratus cloud.
1.3 When the wind blows over the sea then up over a mountain, a layer of stratus cloud can form over the mountain.
This produces rain, mostly on the windward side of the mountain.
This can be called the weather coast.
1.4 Cirrus clouds are very high clouds and look like wisps of cotton wool or hairs.
Cirrus clouds do not bring rain.
1. Hold a clean dry glass upside down under a running tap to make it cold.
Breathe strongly into the glass.
Show the thin layer of water drops inside the glass that come from their breath, Explain that water is in the air, but you cannot see it.
2. Explain how air picks up water when it passes over the sea.
You cannot see the water in the air.
However, if the air rises it becomes small drops of water as you saw in the glass.
You see white cloud where sunlight bounces off the small water drops.
As the water drops grow larger they sink to the bottom of the cloud that then appears dark.
3. Draw the different shapes of cloud.
Use the side of the chalk to show the shapeless stratus.
4. Take the children outside.
What sort of cloud can they see?
Is it raining?
Can they see clouds near mountains?
Draw the clouds and the land.
5. Cloud watch: Record the clouds and rainfall every day for a week.
Can the children describe the clouds that bring rain?
Most thunderstorms occur from December to March in the afternoon over the larger and more mountainous islands.
5.25 Push and pull forces
See diagram 16.4.11: Equal forces on light and heavy objects
See diagram 16.4.1.2: Pushing and pulling
Teach the children to show that a push or pull is a force that can make an object start moving, stop moving or change direction.
Use a big box or pieces of wood with a string or rope attached, a pile of coins, a ruler, a pile of books, a catapult, glass of water,
table cloth.
This lesson should be based completely on the practical applications of force and movement.
Use the suggested instructional materials (and more) to vary demonstrations for push and pull.
Give an example of force which:
1. Starts something moving,
2. Makes something go faster,
3. Makes something go slower,
4. Stops something,
5. Changes the direction of movement of something.
How does a squid swim it squirts water backwards and so it moves forwards?
5.25.1 Push and pull carts
See diagram 16.4.10: Push me, pull me carts
Two students on carts or skateboards or mobile chairs and grab each ends of a rope.
Allow only one child to pull at a time and observe that they both move.
Give them a long stick for pushing each other, or let them push off of each other's hands.
5.25.2 Push and pull a box
See diagram: 17.181: Push and pull
Explain that a force can move things.
What are two ways of moving the big box? [Push the box, pull the box by string.]
What is a force? [A push or a pull.]
Tell a child to push the box and another child to pull the box.
Pushing the box.
In which way are the child's feet pushing? [Away from the box.]
Pulling the box.
In which way are the child's feet pushing? [towards the box.]
Explain to the children that when there is a force in one direction there is also a force in the opposite direction.
Child pulling the box.
What happens if the string breaks? [Child's body moves away from the box and falls over.]
What happens if the ground is slippery? [Feet move towards the box and child falls over.]
5.25.3 Pile of coins
See diagram 16.4.8: Flick a card under a coin
See diagram 16.4.9: Tablecloth pull
1. Put a coin on a playing card.
Flick the playing card with your finger.
Did the playing card move sideways? [Yes]
Did the coin move sideways? [No]
The force was only on the playing card, not the coin.
2. Lay a plate and cutlery on a tablecloth hanging over the table.
Pull down on the tablecloth.
The plate and cutlery remain on the table.
3. Make a pile of coins, a heap of books and put a glass of water on a cloth.
Hit the bottom coin with a ruler.
Does it move? [Yes.]
Do the other coins move sideways? [No.]
Why not? [The force from the ruler was only on the bottom coin.]
4. Pile of books
Pile up books so that you can grip the bottom book.
Pull the bottom book out quickly.
Do other books move sideways? [No.]
Why not? [The pulling force was only on the bottom book.]
5.25.4 Paddle a canoe
Which way does the paddle move? [Backwards.]
Where can you feel the force on the paddle? [On the back of the paddle.]
Which way does the canoe move? [Forwards.]
If you stop paddling does the canoe keep moving or does it stop? [It keeps moving.]
Is there a force on the canoe? [No.]
Hold the paddle upright in the water.
What happens to the canoe? [it moves slower then stops.]
Where can you feel the force on the paddle? [On the front of the paddle.]
Sit in a still canoe and throw out a big stone.
What happens? [The canoe or cart moves in the opposite direction to the stone.]
Explain that for every force in a direction, there is an equal force in the opposite direction.
5.25.5 Link spring balances
Link two spring balances, then pull them apart.
Compare your reading. [They are the same.]
Stacked scales
Put a scale on the floor, put another scale upside down on it, compare the readings.
[They are the same.]
Fire a gun.
Which way does the bullet go? What do you feel on your shoulder? [A force in the opposite direction to the bullet.]
Hold a stone in a catapult.
Pull back.
Let go of the stone.
Why does it move? [It is pushed forward by the rubber in the opposite direction to the pull back.]
Explain that forces are always in pairs.
For every force forward there is an equal force backwards. For every force down there is a force up.
6.0 Weigh in air and water
See diagram 2.7: A heavy object
Use a spring balance, a heavy object that you can attach to the hook and a container of water.
Hold up the spring balance.
Read the weight. [No weight.]
Attach the heavy object.
What happened to the spring in the spring balance? [It was pulled down.]
Read the weight of the object. Lower the heavy object into the water.
What is the weight now? [Less than before.]
Why is it less? [The water pushed up on the object.
The spring in the spring balance was pushed up.]
Stand in a river.
Pick up the biggest stone you can from the bottom of the river.
Now lift the stone above the water.
What happens? [the stone feels much heavier.]
Why? [The water is no longer pushing up on the stone.]
What are the two kinds of force? [Push or pull.]
5.26 Air pressure in all directions
See diagram: 12.272: Spurting tennis ball
See diagram 12.305.2: Air supports water in a glass tube
See diagram 12.305: Two plumber's force cups
Teach the children to show that air pressure is in all directions.
1. Inflate a balloon and tie the inlet.
Squeeze the balloon.
Can you feel the air pushing when you squeeze the bag. [Yes.]
When the air pushes this is called air pressure.
2. Rub together two coins of the same size.
You can separate them easily.
Now wet the touching surfaces of the coins with water, and rub them together.
Can you pull them apart easily? [No.]
Press a dry coin on your forehead and on the underside of your arm.
It falls off easily.
do this again with a wet coin.
What happens? [It sticks to you.]
Why does this happen? [The water pushes out any air between the coins and your skin.
Air is pressing in all directions on the coins.]
3. Fill a jar with water right to the top.
Put a card on top of the jar so that there is no air inside and the top is completely covered.
Put one hand firmly on the card and carefully turn the jar upside down with the other hand.
Now take away the hand from the card.
The water should stay inside the jar.
What is pressing up on the card to stop the water from falling out? [Air.]
4. Put your finger over the hole at the end of a bicycle pump and press the handle in as far as you can.
Let the handle go.
It will be pushed back out.
What pushed the handle out? [Air pressure.]
Where you can find air. [All around us.]
5. Put some hot water in a coffee or milk tin.
Put on the lid and heat the tin.
What happens? [The lid flies off.]
Why? [The hot water heats the air in the tin.
The heated air expands and increases the air pressure inside the tin pushing the lid off.]
During the observation, do not have your face too close to the tin.
6. Put some water in a large tin can which has straight sides and a screw on cap.
Heat the can.
When steam comes out screw on the lid and take away the burner.
The can will collapse in all directions, because of air pressure.
What is all around us? [Air.]
What does it do to us? [Air presses on us.]
In which direction does air press? [All directions.]
7. Heat the can to boiling point, remove the flame and release cold water on it from a tap or bucket.
The can similarly collapses.
8. Explain that cyclones occur when the air pressure is very low.
This causes air to rush in towards the low pressure area causing strong winds.
5.27 Germination test
See diagram 9.3.49: Germination test
Teach the students to test the germination of seeds.
Use seed samples, wet newspaper, plate or saucer, water.
Not every seed will germinate, but instead of planting two or more seeds in each hole use a germination test to estimate how many
seeds will germinate.
When seeds remain alive and can germinate to form baby plants, we say the seeds are viable.
It is a good idea to test the viability of seeds before planting, otherwise you waste time and effort on useless seeds.
To test the viability of small seeds, soak 20 seeds for an hour then put them on wet newspaper in a closed container.
After a few days count the number of seeds which produce healthy roots and calculate the percentage germination.
Groups of four students.
1. Give 20 seeds to each group of four students.
Show them how to soak the seeds first.
Then tell them how to do the germination test: you can use half coconut shells for containers.
After four or five days count the number of germinated seeds and work out the germination percentage.
2. If in the germination test on 20 seeds, 16 form roots, % germination = 16 / 20 x 100 = 80 %
If you plant 2000 seeds, how many will germinate? 2000 x 80 / 100 = 1600 seeds
If you want 1000 plants to grow, how many seeds should you plant? Let N = the number of seeds you should plant
80 / 100 x N = 1000
N = 1000 x 100 / 80 = 1 250 seeds
3. Compare there percentage germination of melon, corn and bean seeds
Are seeds alive? Do they breathe? [Yes, they are alive. They breathe very slowly.]
What are the four things that happen during germination? [1. Water enters the seed.
2. The seed becomes active.
3. The seed breathes more quickly.
4. A new plant starts to grow.]
What are the three stages of germination? [1. The seed swells and the radicle grows out.
2. The stem grows into a loop the stem straightens. 3. The cotyledons and leaves are pushed up out of the ground.]
5.28 Seed depth
See diagram 9.113.2d: Seeds planted at different levels
See diagram 9.113.4: Maize
Germinate a maize grain
Teach the children to observe what happens when seeds are planted at different depths.
Use maize (corn) and bean seeds and a prepared seed bed.
Although we call maize a "seed", in botany it is a "fruit"!
The best planting depth is usually 2.0 cm in wet soil and 4.0 cm in dry soil.
1. The aim of this experiment is to see what happens when seeds are planted at different depths.
2. Draw a diagram on the chalkboard to show the design of the experiment.
3. Show how to plant the seeds and observe results.
4. Which depth is best for this seed?
Depth of Seed
Which depth is best?
Plant 6 maize seeds and 6 bean seeds
Number of days 7 days 14 days 21 days 28 days
Surface only 7 days 14 days 21 days 28 days
1 finger deep 7 days 14 days 21 days 28 days
2 fingers deep 7 days 14 days 21 days 28 days
3 fingers deep 7 days 14 days 21 days 28 days
4 fingers deep 7 days 14 days 21 days 28 days
5 fingers deep 7 days 14 days 21 days 28 days
6 fingers deep 7 days 14 days 21 days 28 days
7 one hand deep 7 days 14 days 21 days 28 days
5 The two types of germination:
1. The seed coats come out of the ground (epigeal germination)
2. The seed coats remains under the ground (hypogeal germination)
3. Note the different types of seeds and the germination styles of each.
4. Cut longitudinal and transverse sections of the maize grain.
Be Careful Soak it for a day in water before attempting to cut it!
Observe the shapes seen and compare with the diagram.
5.29.1 Germinate maize grain
Teach the children to describe the germination of a maize grain.
See diagram 9.113.4: Maize
Germinate a maize grain
Use maize grain, rice or sorghum, jar, wet paper, knife, magnifying glasses.
The seed of maize, rice and sorghum is really a fruit with a hard tight wall.
It is called a grain.
In England "corn" means wheat.
In USA "corn" means maize, i.e. Indian corn.
Use maize grain soaked in water for a few days, knife and magnifying glasses.
About one week before the lesson plant some soaked maize grains.
A shoot is the stem and the leaves.
Learn to cut soaked grains longitudinally and transversely with a knife.
Be Careful!
1. Show the dry maize grains and soaked maize grains.
What is the difference? [Soaked maize grains are softer and fatter.]
2. Look at the germinating grain.
Can you see the first root? The white shoot cap? The first leaves breaking through the shoot cap?
3. Cut a soaked maize grain in longitudinal half.
Can you see its parts? When there is enough water, air and warmth, the new plant will start to grow.
This is called germination.
When all this stored food has been used up, the plant will make its own food in its leaves.
4. maize germination project.
Plant some soaked maize grain.
How many days before: 1. germination, 2. shoot cap shows, 3. first leaves break through the shoot cap?
5.30 Plant roots absorb water
See diagram 9.195: Plant roots absorb water.
See diagram 9.73.3: Root hair in soil, TS root
Teach the children to show that plants take in water.
Use small plants such as Amaranths, glass jars, ink, cooking oil, water.
In this lesson you can show that plants take up water in two ways: see whether the ink gets into the plant.
Put the plants in the inky
1. Give out plants and inky water.
Can the plants take in water? How can you show this? [Put plants in inky water and water.
Remove them out after a few hours.]
2. How you can see how much water plants take in? [Put some oil on the water, then the water cannot evaporate.]
Draw the diagram.
How will you know that the water went into the plant and nowhere else? [The inky water will show us where the plant went.]
Set up the demonstration and put it aside.
3. Give out small plants with well washed roots, and magnifying glasses. Can they see the tiny root hairs?
Take the plant out of the inky water. Break open the stem.
Can they see the ink inside? What can you learn from this? [Roots take in water.]
Look at the water with the oil in top.
Is the water level the same? [No, it has gone down.]
Why did it go down? [Some water went into the plant.]
Look at the control.
Did the water level go down? [No.]
Why not? [There was no plant to take in the water.]
4. Put some ink in water then put the plant roots in it.
After a few hours break open the stem with their thumb nails and they will see the ink in the stem
5. Put the plant in water and add about one cm thick of cooking oil.
Mark the level of the water.
After about one day the level of the water drops.
If you have another jar with oil floating on it, you will notice that the water level in this jar has not dropped.
This is called a control.
It shows that the water level dropped, because the plant absorbed it.
If you look at the roots of a small plant, you can see what it uses to take in water.
It takes in water through the root hairs.
5.31 Leaves lose water
See diagram 9.194.1: Transpiration in plastic bag
Teach the children to show that plant leaves give out water.
Use plastic bags, string, small tree with soft green leaves.
Plants take water from the soil into their roots through root hairs.
From there, water moves up the stem through to the leaves.
1. You will do an experiment to see what happens when a plastic bag is tied over leaves.
2. Show a dry plastic bag, and a tree branch with dry green leaves.
Tie the bag over the leaves and return to it later in the day.
Show the bag over the leaves and ask them to tell you what they see inside.
[Water.]
Where did the water come from? [It comes from the leaves.]
Draw the bag over the leaves.
Explain that all plants lose water through their leaves.
3. How can you prove that water comes from the leaves and not the stem? [Tie the plastic bag around the stem, the leaves pulled off.
No water will form in the bag.]
Draw a plant then draw arrows on it to show how water moves through it.
Write labels on the arrows.
[Soil water, root hairs, stem, leaves, air.]
Plants take water from the soil into their roots through their tiny root hairs.
The water then goes up the stem into the leaves, then into the air.
5.32 Protect mangroves
Teach the children to explain why we should keep mangroves growing.
Use pictures of specimens of mangroves or a natural mangrove environment close to the school.
Either prepare to visit mangroves or have some pictures of typical mangroves.
It is preferable to have both, for a lasting impression.
Mangroves are big trees that can live in the shallow sea water near the shore.
Their roots grow in the mud or sand and are under water at high tide.
Some people want to cut down the mangroves to use the wood or to get rid of mosquitoes or to clean trees from the shore.
Some people do not like mangrove swamps, because they cannot walk through them easily.
Why should you keep mangroves?
1. They are very interesting plants.
Many years ago they lived in the forest, but they learned to live in shallow sea water and they developed special parts to do this.
Some mangroves have roots that grow up through the mud to get air.
Some mangroves have tall stilt roots for holding onto rocky land.
Some mangrove seeds grow into small plants still attached to the tree, others seeds form a long root to spear into the mud when it falls.
Can they see anything else that is special about mangroves?
2. Mangroves hold the mud together and can make new land.
If we kill all the mangroves, the mud will be washed into the sea.
Many animals live in the mud and are part of the food chain.
Many small fish live among the mangroves where they can hide.
When these fish grow bigger, they swim into the sea.
3. When mangrove leaves die they fall directly into the sea.
These leaves act as a fertilizer.
4. Mangroves have been part of the scenery of the country for a long time.
We should not destroy your natural environment, but keep it for the next generation to enjoy and learn from.
5. Visit a mangrove swamp.
How many different kinds of animals can they find living in the mangrove trees and in the mud? Dig a deep hole in the mud.
Can they smell a gas produced by anaerobic bacteria living in the airless mud? [Hydrogen sulfide.]
Can you recognize Red Mangrove (Rhizophora) which possesses silt roots for absorption from the muddy surface?
Which of them possesses breathing roots to keep the plant well aerated? [White mangrove, Avicennia.]
Taste the leaves of the two plants.
Which of them tastes more salty? [Avicennia leaves, because they have salt glands on the upper leaf.
The lenticels are concentrated on the upper part of the breathing roots or pneumatophores.]
5.33 Different rocks
Teach the children to describe different rocks, make up groups of rocks with the same property, and put a new rock
in one of those groups.
Prepare a simple rock classification the week before this lesson, collect enough rocks so that each group of
children has the same kinds of rocks.
You can break a big rock into pieces by wrapping it in a cloth then hitting it with a hammer.
Use the following pieces:
1. rounded stones from rivers,
2. pieces of gravel,
3. pieces of stone showing layers,
4. pieces of stone showing crystals,
5. stone that makes a mark when rubbed on paper (we call this "streak").
You will also need paper, nails and a magnifying glass for each group.
Divide the class into groups of four children.
1. Give each group one of each kind of stone (a) to (e), and a magnifying glass.
Is the stone hard or soft?
Can you break it into pieces?'
Can you scratch it with a nail?
What colour is the stone?
Is the stone made of layers?
Is the stone shiny or dull? [It may contain shiny crystals.]
Does the stone feel smooth or rough?
Rub the stone on a piece of paper.
What colour does it make on the paper?
2. Stone Sculptures
Show the children how to rub or cut soft stone into different shapes.
Teach the children to make a collection of the different types of rocks near the school.
Use rock types from different locations, boxes for the rocks, a hammer and a magnifying glasses.
Before the lesson collect different types or rocks from your area.
Include rocks from cliff faces, streams, and the sea shore.
Also, tell the children to bring rocks from home.
1. The three main types of rocks are as follows:
1.1 Igneous rocks are formed from volcanoes.
The rocks have cooled from very hot liquid rock.
You can see whole crystals in them.
1.2 Sedimentary rocks are formed form particles of other rocks carried into rivers, lakes and the sea and then squeezed together.
You can usually see the layers in the rock.
Coral reef limestone are also classified as sedimentary rocks.
1.3 Metamorphic rocks were once igneous or sedimentary rocks, but have been squeezed and heated again.
Do you know where the main rocks are found and their uses in your country?
2. Show the collection of rocks.
Divide the rocks into those obtained from:
2.1 rivers, rounded pebbles, pieces from the edge of the river,
2.2 Sea shore, pieces of limestone, rounded stones,
2.3 Deep in the soil,
2.4 Cliff faces, pieces of rock.
3. Wash the stones.
Divide the children into two groups:
3.1 Stones have crystals, they shine when you turn the rock.
These are igneous rocks from volcanoes.
3.2 Stones do not have crystals, usually have layers.
These are sedimentary rocks formed at the bottom of lakes and the sea.
4. Look at the igneous rocks.
Are the crystals darker or lighter than the rest of the rock?
How big are the crystals?
5. Look at the sedimentary rocks.
Can you see the layers?
Are all the particles the same size?
How big are the particles?
6. The sedimentary rock limestone may contain shells.
If you put some acid on limestone, it forms bubbles of carbon dioxide gas.
7. Make a display of their rock collection.
Label it:
igneous, where found, description of crystals, colours, layers.
metamorphic, where found, description of crystals, colours, layers.
sedimentary, where found, description of crystals, colours, layers.
8. Name the rocks you find:
Basalt: Heavy, dark rock, with very small crystals, some have green colour
Andesite: Light coloured, with very small crystals
Limestone: Looks dirty, no layers, fizzes in acid
Mudstone: Sedimentary with fine particles, layered, easily broken
Sandstone: Sedimentary, separate sand grains can be seen
Conglomerate: Sedimentary, has mixture of rounded stones and smaller particles.
1.32 Different rocks
Teach the children to describe different rocks, make up groups of rocks with the same property, and put new rocks in a group.
Use the following:
1.1 rounded stones from rivers,
1.2 pieces of gravel that are small stones with sharp edges often used to make roads,
1.3 pieces of stone showing layers,
1.4 pieces of stone showing crystals,
1.5 stone that makes a mark when rubbed on paper, called "streak".
You will also need paper, nails and a magnifier for each group.
You will need enough rocks so that each group of children has the same kinds of rocks.
Break a big rock into pieces by wrapping it in a cloth then hitting it with a hammer.
1. Give each group each kind of stone 1.1 to 1.5. and a magnifier.
Is the stone hard or soft?
Can you break it into pieces?
Can you scratch it with a nail?
What colour is the stone?
Is the stone made of layers?
Is the stone shiny or dull? [It may contain shiny crystals.]
Does the stone feel smooth or rough?
Rub the stone on a piece of paper.
What colour does it make on the paper?
2. Stone Sculptures
Show how to rub or cut soft stone into different shapes.
5.34 Soil profiles
See diagram: 6.26: Soil profiles
Teach the children to collect samples of different kinds of soils and what you see in them.
1. Use a sharp spade to dig the soil profiles and glass jars or pieces of glass.
To dig a soil profile, find a flat area free of stones.
Dig down vertically on three sides of a square.
Dig the fourth side on a slope to make a wedge, then lift up the soil.
The top few centimetres of soil are dark in colour, because rotten plants and animals form a black sticky substance called humus.
The topsoil is a layer containing the humus and most of the plant roots.
Below it is the subsoil that contains mostly sand, stones and clay and some big tap roots.
Below that is solid rock.
The subsoil and topsoil may have formed from these rocks or the soil may have been dumped on the rocks by a river or water washing down.
2. Record how many kinds of soil profiles you can collect:
2.1 Loam soil is a good garden soil found in river valleys.
It may be black or red with much humus in the topsoil.
Soil from a hill will have less topsoil than soil from a river valley.
2.2 Sandy soil is found just behind a beach or near the bend in a running river.
It does not have much humus and dries out easily.
2.3 Clay soil is hard to dig in dry weather and very sticky in wet weather.
It takes a long time to dry out and when it does it forms cracks. It usually has a red to brown colour.
2.4 Mangrove soils and poorly drained soils have a grey colour and often a funny smell.
3. Show the children how to dig a soil profile.
4. Collect different soil profiles.
Measure the depth of topsoil and subsoil, note the colours and record where it was found.
5. Describe where different kinds of soil are found and why they are found there.
What kinds of plants are growing on them Are soils good for gardens
6. Dig soil profiles in a new garden, old garden, in a forest and on a steep slope.
What differences do you see? Make a table and record your observations.
5.36 Cover crops
See diagram 6.65.4: Cover crops, Centro, Siratro, Puero
Teach the children to name which plants are suitable for cover crops or green manure and explain how they improve the soil.
Use specimens of common plants used for cover crops and green manure or diagrams of the different plants.
Ask an agricultural officer to show you how to prepare these seeds or cuttings for planting.
1. Draw a diagram of a bed of soil on the chalkboard.
Hold your arm above the diagram.
What would my arm protect the soil from? [Sunlight, rain.]
Why should we protect the soil from sunlight? [If the soil is too hot, if seeds cannot germinate, if water is lost from the soil.]
Why should you protect soil from rain? [Heavy raindrops make the soil splash up then get washed away.]
2. What can you use to protect the soil?
Can you use sheets of iron? [No.]
Can you use trees? [Yes, but when the trees grow big they will use most of the light and water so you can't grow other crops.]
You use plants that do not grow high, but cover all the ground with lots of leaves, e.g. legumes called Puero, Centro and Calopogonium.
3. A legume cover crop can:
3.1. Lower soil temperature and evaporation of water,
3.2 Protect soil from splash erosion, but let water trickle down into the soil
3.3. Shade the weeds so they cannot grow,
3.4 Add humus and nitrogen fertilizer to the soil when the leaves die.
4. If you are not using land for some time, e.g. during the school holidays, protect the soil and keep weeds out by planting a cover
crop.
However, clearing plants is hard work.
If you plant an upright legume such as cow pea or mung bean, you can easily dig them into the soil.
This is called green manure.
About 3-6 weeks after digging, the plants rot in the soil and the plant foods will be available for their next crop.
5. Show the legume plants and let the children feel the soil under a cover crop.
6. Sowing a of green manure.
Note that Centro has hard seeds that take a long time to germinate unless you treat them with boiling water.
Puero and Calopogonium grow well in shade under leaves.
You cannot dig in green manure crops under tree crops, because it would damage the roots.
Other good legumes are Hetero and Siratro that produce good grains for cattle and Stylo that is good at smothering weeds.
5.37 Rain on slopes
See diagram: 24.4.6: Rain on slopes
Teach the children to describe what happens when water falls on different slopes.
Use:
1. One to four jam tins with holes punched in the bottom,
2. A soil ridge that is flat on top, has one side sloping steeply and the other side sloping gradually
Teach this lesson outside in the garden.
1. Show to how to make two ridges that are flat on top.
One ridge has steep sides and the other has gradual sloping sides.
Leave no plants or stones on the ridge, only fine soil.
2. Give each group a tin with holes in the bottom.
Show how to fill the tin with water and make artificial rain.
3. Make rain on the gradual slope.
Tell the children what happens. [Some water just soaks into the soil, some water runs down the slope and carries soil down.]
4. Make rain on the steep slope.
Explain what happens.
[Much soil is carried down the slopes.]
5 .Where should you make gardens? [On flat ground or else the soil will be washed away.]
6. Do the same, but cover the soil with grass.
Grass stops the soil from being carried away.
5.39 Make clay pots
Teach the children to make a pot from sand and clay.
Use fresh sand and different types of clay, banana fibre, round stones, fuel wood.
About a week before the lesson, collect the same amount of red clay and washed sand.
Mix them in equal parts by pounding with a wide stick.
Wrap it in banana leaves to keep it moist.
1. Explain that this method of making pots is very old and is still is in some parts of the world.
2. Give each group a lump of damp clay.
Divide it into four smaller pieces.
Flatten each lump with a round stone.
3. Twist the banana fibre to make a hoop for a stand.
4. Mould one piece over a stone to make the bowl shape.
Put this on the hoop.
Add flat pieces to build up the walls, keeping the stone inside.
Cut the lip smooth with a coconut fibre and smooth the edge with wet fingers, take the stone out.
Write your name in the side with a small stick.
5. Leave the pot to dry for 1-4 weeks.
6. Firing the pot: Get lots of little softwood sticks.
Put the pot on top of some, then build a house of sticks all around the pot.
Set fire to the house of sticks.
Encourage the children to visit different locations where pots are made from clay.
5.41 Keep water clean
Teach the children to explain how to keep water clean for humans, animals and plants.
Use sample of pure drinking and polluted water, examples of purifying processes.
Before the lesson visit a local source of drinking water or a river and the seashore.
Note where the water is clean.
Use samples of good drinking water and smelly polluted water that is unfit for drinking.
Bring some rubbish found in a river or on the seashore.
1. Show the good samples of good drinking water and water unfit for drinking.
Tell them to look at the samples, smell them and tell you the difference.
Why do you need clean water? [Dirty water can make us sick.]
Explain that dirty water can contain bacteria that make us sick.
Bacteria are so small that you cannot see them with your naked eyes.
You need a microscope to see them.
2. How can you be sure that water is clean and will not make us sick?
2.1. Boil water for babies.
2.2. Drink rainwater.
2.3. Drink clean water from wells or rivers.
2.4. Drink clean water from treated sources.
3. How you can you make clean water dirty:
3.1 Throwing rubbish or dead animals in the river.
3.2 People putting their faeces or urine in the river.
Toilets must be 20 metres from the river otherwise bacteria from sick people can get into the water.
3.3 Chemicals such as insecticides and weedicides can wash into the river from sprayed crops.
Soil can wash into the river to make it muddy.
4. How you can keep rivers clean:
4.1 Bury all rubbish.
4.2 Build toilets at least 20 m from the river and at least one metre deep.
4.3 Do not let agricultural chemicals wash into rivers.
Bury unused chemicals.
4.4 Use contour banks to stop soil washing into rivers.
4.5 Do plants and animals in the rivers and sea need clean water? [Yes.]
How can dirty water hurt them? Disease and chemicals can kill them.
Muddy water and rubbish stop them getting light.
Muddy water can kill coral.
Plastic rubbish can kill some fish if they eat it.
5.1 Visit a pig latrine.
Is it 20 metres from a river, houses, pig yards, wells?
Is it more than one metre deep?
Does it have a cover?
re there any flies around it?
5.2 Visit a river.
Is there any rubbish in it?
Is muddy water caused by garden soil washing into it?
an chemicals get into it?
5.3 Visit the seashore.
Is the water muddy?
Can animals and plants live in the muddy water?
Collect the flotsam washed up on the beach.
How did it get there?
Does it contain plastics?
Plastics do not rot quickly and remain rubbish for a long time.
5.42 Heated air expands
See diagram 20.1.1 : Heated air expands
Teach the children to describe what happens when a bottle is heated and then cooled.
Explain that air expands when heated and contracts when cooled?
Use a bottle, plastic tube from ball pen, burner, glass jar.
Be careful! This experiment is dangerous if you heat the bottle too much.
Before the lesson, practice the demonstration in a preparation room before doing it in front of children.
Strict adherence to instructions is very essential here if accidents are to be avoided.
Demonstration preferred
1. Give out the materials and tell the children to push the ball pen tube into the hole in the cork.
Push the cork into the mouth of the bottle, so that no air can leak out around the side of the cork,
Hold the neck of the bottle with a piece of rag or paper and tip the bottle so that the end of the tube is about three cm under the level
of the water in the tin.
Heat the bottle gently with the burner for a few minutes and watch what happens. [Bubbles come out of the tube in the water.]
2. Stop heating the bottle.
Put out the burner flame.
Keep the end of the tube under the water and watch what happens as the bottle cools down.
[Water is sucked into the tube.]
3. Explain why it is dangerous to heat closed bottles or gas cylinders because when gases are heated they expand.
If expansion occurs very quickly this is called an explosion.
5.43 Burn to make carbon
See diagram 3.1.2.4: Bunsen burner flame, Candle flame
Teach the children to show that all living things contain carbon.
Use a candle or burner, old torch battery from a radio, paper, pencil, dry leaves, insects, sugar, food, tin lids, iron nails, tongs or a
holder to hold nails in the fire.
In this lesson you will burn a variety of materials that are alive or were once alive and in each case you will show that when the burning
is completed only carbon is left.
Carbon is an element represented by the symbol C.
Oxygen is represented with O.
If carbon is heated to a very high temperature, it can form the gas carbon dioxide or CO.
So if you heat the substances in this experiment to high temperatures you would not have any carbon left, it would all have turned into
carbon dioxide gas.
Break open the battery and take out the black rod in the middle.
Dig a hole outside where there is good topsoil containing plenty of black humus.
1. Give out the candle or burner, tongs and things to be burned.
Hold a tin lid in the candle flame.
Cool the lid then wipe off the black stuff called soot.
Explain that this black stuff is called carbon.
Put some carbon on your fingers.
2. Make a pencil mark on paper then rub your finger on it.
The black mark on your finger is carbon.
3. Show the black rod in the centre of the battery.
It is carbon.
4. Burn paper, an insect, piece of meat or sweet potato.
What happens to them? [They become black.]
What is the black stuff? [Carbon.]
5. Heat up some sugar on a tin lid.
What happens to the sugar? [It burns to form carbon.]
6. Take the children outside to the hole.
How is the topsoil different from the subsoil? [It is darker.]
What is in the topsoil? [Rotten plants and animals.]
Why is it black? [The rotten plants and animals become carbon.]
Explain that the substance from rotten plants and animals that contain carbon is called humus.
7. Take a piece of burnt wood, it is called charcoal.
Heat it until it glows red.
Why does it get smaller? [The carbon is changed into carbon dioxide gas.]
Relate this to what happens in a charcoal pressing iron and when used for cooking locally.
8. Burn some feathers or hair.
Carbon is formed, but there is also a strong small.
The smell comes from another substance called sulfur S, which burns to form the gas sulfur dioxide, SO2
5.44 Soil fertilizer trial
See diagram 5.44: Fertilizer trial
Teach the children to set up a fertilizer trial to test whether fertilizer makes crops grow better.
Use a piece of land already dug, wooden pegs, maize seeds or pineapple suckers or other planting material.
Ask an agricultural officer for advice on which fertilizer to use for a trial.
The plant nutrients are divided into the following three classes:
1. Primary plant nutrients, nitrogen N, phosphorus P, and potassium K.
(Potash is potassium oxide).
One or more of these usually limits the yield of a crop i.e. if there were more of this plant nutrient in the soil the yield would be greater.
These are the most important plant nutrients, which make from 2-6 % of the dry weight of plants.
2. Secondary plant nutrients, sulfur S, iron Fe, calcium Ca and Magnesium Mg.
These nutrients are needed in smaller amounts than the primary plant nutrients for normal growth.
There is usually enough of these in the soil for good crop yields.
3. Micronutrients (sometimes called trace elements] include:
boron B, chlorine Cl, cobalt Co, copper Cu, manganese Mn, molybdenum Mo and zinc Zn.
These are needed in very tiny amounts for the normal growth of some plants.
If a soil does not have enough of a particular plant nutrient, e.g. nitrogen, we say that the soil is deficient in nitrogen.
The only sure way to find out whether a soil is deficient in any plant nutrients is to ask a field officer of the Department of Agriculture
to send some of the soil to a laboratory for chemical testing.
However, we can tell if the soil is deficient in plant nutrients by examining our crop plants carefully.
If a plant does not look healthy, because there is not enough plant nutrient we say that it shows deficiency symptoms.
When there is not enough, the plant shows plant nutrient deficiency symptoms:
4. Nitrogen deficiency: The plants are small and you have few leaves which are pale green or yellow.
The lower leaves look burnt and die early.
5. Phosphorus deficiency
The plants are small and do not grow well.
The leaves are a blue-green colour and are usually purple underneath.
The lower leaves die early.
They take a long time to produce fruit which are small and badly shaped.
6. Potassium (potash) deficiency
The plants have small main shoots, but many side shoots.
The leaves have dead white areas on the leaf edges and later die.
7. sulfur deficiency
The plants are small with pale green upper leaves.
8. Calcium deficiency
The plants are small with unusually shaped leaves.
The shoot tips may die.
9. Magnesium deficiency
The leaves have green veins, but are pale yellow in between.
10. Iron deficiency
The younger leaves look yellow.
The lack of healthy green colour in the leaves is called chlorosis and this may be due to a deficiency in one or more plant nutrients.
11. A fertilizer trial is designed to try out different kinds of fertilizer in different amounts to see if fertilizer makes crops grow better.
12. Show the children how to mark out with wooden pegs the corners A. B. C. D and the mid points I, II, III, IV.
The rows should all be the same size.
The seeds or cuttings should be all planted the same distance apart in the rows.
3. Fertilizer is applied to the experiment plots A and D.
No fertilizer is applied to plots B and C called control.
4. Draw the trial in an exercise book, write down the date.
5. Compare the crops in A and D with plots B and C plots.
Does the fertilizer improve the crop yield?
6. Set up a long trial using tree crops.