# People power

This lesson for students aged 7–11 is about what energy is, where it comes from, and how it is stored.

## Lesson outline

Step 1: Engage and elicit

Show the pupils a picture of Saiful and his weighing chair and/or a clip from Saiful’s second Lecture showing the weight of what Saiful ate was different to what he excreted. Pupils think and talk using a concept cartoon to stimulate discussion. Where is the missing 3.5kg? Take all pupil responses without judgement. Question to probe their understanding and concepts around this issue. Allow the pupils to feel the weight of 3.5kg. If Saiful put this much weight on each week, how much would he weigh in a year?

Step 2: Explore the different foods that the pupils eat on a daily basis

Remind the children of all of the food that Saiful weighed for his experiment. Ask the children if they can complete a food diary listing the foods they have eaten over the last 24 hours. Make a class list of some of the foods on the board. Can these foods be grouped?

Remind the children about the different food groups and what they do: Protein, carbohydrates, dairy, fruit & vegetables and sugars & fats. Ask the children if some of these foods are better than others. Provide each group with question stems (what, where, when how, could, why) or a question matrix and encourage the children to come up with some interesting questions to ask each other about their diets. Allow the children some time to interview another pupil about their diet using their questions.

Step 3: Explain. Children begin to show their understanding of different food types and can explain which types of food contain more energy (Kj)

Show the pupils the food label on the PowerPoint. This shows both KJ (kilojoules) and Kcal (kilocalories). Inform them that children need 1000–2000 kcals each depending on age and physical activity.

Watch the video clip of the burning of foods including pork scratchings, etc.

Show the pupils a selection of foods and ask them to make a prediction. Which food will contain the most energy? Provide each child with a food label or a packet/tin of food with a clear food label. Ask them to find how many Kcals their food contains. Ask the children to make an ordered line starting with the most energy (Kj) and going to the least amount of energy (Kj). Repeat with calories. Did the order of food change? Repeat with amounts of carbohydrates, protein, fat etc.

Ask the children after this activity which type of foods contain the most energy/Kcals. Ask the children what would happen if we ate more than our bodies could use? Could we store it for later? Tell the children that is exactly what our bodies are designed to do. We store unused energy/food as fat.

Step 4: Explore. Humans cannot create their own food. They have to eat animals and/or plants. Where do other animals and plants get their food from?

Check pupil understanding about where a beef burger or bacon etc. comes from. Watch the clip from the CHRISTMAS LECTURES of the food chain. This food chain started with a plant that grows in water (plankton). Do all food chains start with a plant? Can the children identify any food chains they believe that don’t?

Watch the video clip of the cuddly toy food chain from the Lecture.

Give each child a picture card (from a range of plants, animals and humans) ask the children to circulate the room until they find another pupil with a picture card that they can eat. Continue until a food chain has been made.

What do plants eat? Introduce pupils to the idea that plants make their own food and that they use the sun to do this.

To round off this lesson ask draw together a plenary discussion about whether the children, from what they have learnt, think that ultimately if all food chains start with plants, whether that makes humans solar powered? Discuss their thoughts on this.

## Objectives

The underpinning big idea

What is energy and where does it come from? How can we best make use of it, and how can we store energy to use later on?

Children will be able to work scientifically by:

• Asking relevant questions and using different types of scientific enquiries to answer them
• Making systematic and careful observations and, gathering, recording, classifying and presenting data in a variety of ways to help in answering questions

Children will learn to:

• Identify that animals, including humans, need the right types and amount of nutrition, and that they cannot make their own food; they get nutrition (and energy) from what they eat
• Describe how animals obtain their food from plants and other animals, using the idea of a simple food chain, and identify and name different sources of food

Cross-curricular opportunities:
Maths curriculum/measurement

• compare and order mass, volume/capacity
• measure, compare, add and subtract: mass (kg/g); volume/capacity (l/ml)

## Video clips

Download the teachers' guide for instructions on how to use these clips:

Weighing food:

Burning food:

Food chains:

## Lesson material

Download the full teachers' guide.

You'll also need the PowerPoint presentation.

### Watch the full lectures

View the full CHRISTMAS LECTURES, 'Supercharged: Fuelling the future', on the Ri Channel: richannel.org/christmas-lectures

Primary resources produced by the University of Manchester's Science & Engineering Education Research and Innovation Hub and the Primary Science Teaching Trust.