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Ask the learners when they have used up their energy, would they be able to get more energy.
Ask learners what they use in their homes to keep warm or to cook food. Ask them if they know what their grandparents used.
Possible answers: wood, gas, paraffin, electricity
Explain that when wood, coal or candles burn they give off heat. We call them fuels. We need energy to cook our food, to give us light, and to move quickly in a car, train, taxi or bus. We also need fuels to work big machines in factories. We cannot live without fuels.
Read through the facts in the worksheet and explain: Examples: Electrical energy - bolt of lightning, batteries in a cell phone, sun, lightbulb.
Ask learners to complete the worksheet.
Teacher Input 3
Divide learners into groups of 3 or 5.
Present each group with a set of flash cards bearing pictures of renewable and non-renewable energy sources.
Ask the groups to sort the pictures into a renewable and non-renewable pile.
Tell learners that we will now look at what they have learnt about energy in Grade 4.
Hint: You may make sets of flash cards bearing some or all of the pictures or cut out pictures from a magazine. The groups do not all have to work with the same pictures. Give the actual item to some groups.
As each appliance / object is shown, ask learners to write the form of energy that is produced by different appliances and objects in their Worksheets. (Worksheet B).
Give each learner a peanut (check that learners are not allergic to peanuts) or a small sweet for energy.
After they have eaten their treat, let them use the energy to dance to music.
Tell learners that they have learnt in grade 4 that energy gives our bodies the ability to work.
Ask learners to google at home about the products produced by animals and report back.
The food we eat is our source of energy.
The sun is our main source of energy. This energy is transferred into plants where they use it to make a sugary substance called glucose. This food can be changed again into sugar, starch, oil and protein and stored in different parts of the plant. When the plants are eaten, the energy in the food is transferred into the animal. The animal, in turn, produces products like milk, cream, yoghurt, butter, cheese, meat, chicken, eggs, sheep (wool), leather (skins of pigs, cattle, sheep, goats, alligators).
Ask learners what they can remember about input and output.
Allow time for some answers.
Explain that whenever anything happens, energy is transferred from one component into another. People, machines and appliances need an energy input to work. They also have an energy output that may be useful.
Have learners copy images from the PowerPoint Presentation to make colourful posters about Input and Output Energy – posters should be displayed in the classroom. Inspire the learners to make a special effort with their posters because it will be displayed in the classroom.
The video shows via an experiment how to measure the energy released from a burning peanut.
Ask learners if they know how we measure the energy in food?
Answer: in kilojoules (kJ)
The energy value of food tells us how much energy that food is worth to our bodies as fuel. This information is called “nutritional information” and we can find it on the boxes and packets that our food comes in.
Our bodies need energy to jump, run around, ride a bicycle, dance, play games, breathe and keep warm. Our hearts need energy to beat. We will die if our hearts stop beating. Our brains use energy to think.
As you are growing, your body needs energy to produce new cells and to fix old cells. Our bodies get all this energy from the food that we eat.
Energy is stored in food as chemical energy (potential, stored energy). When we eat the food, the energy is released and used by our bodies. If we eat too many foods with a lot of kilojoules of energy each day, the extra energy may be stored as fat and we will gain weight. If we are very active (jump, run and walk fast) then we can burn these kilojoules and our weight will stay the same.
Learner Activity 3
At the end of break time, ask the learners to collect litter (sweet wrappers, chip packets, etc.) around the playground and bring it to the class or ask learners a day before this lesson to bring empty food packaging from home.
Ask learners to look at the nutritional information on the litter packets which they have collected and discuss the number of kilojoules in each item.
Teacher Input 5
Have a variety of empty food packaging on hand, for example cereal boxes, food wrappers, milk cartons and ask learners to also bring some to school. Bar graph (on the board): Types of vegetables and fruit that the learners do not eat.
Ask learners that, apart from the name of the food, what other information do they see on the packages or boxes?
Draw their attention to the following information on the packages: Serving Size, Servings per Container or Package, Calories and Calories From Fat, Calories per Gram.
Explain the meaning of the types of information to the learners as found in Fact Sheet 1.
Learner Activity 4
Tell the learners that they will have to apply their Mathematical knowledge to interpret the bar graph on Worksheet D.
Guide learners as they complete the questions of Worksheet D.
Teacher Input 6
Show Video Clip 2 (3.57 minutes). Coal power generation is explained in this video.