• Quick retrieval from earlier learning (Identify energy stores in everyday situations). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. Which energy store is the main one here: a cup of hot cocoa? (gravitational potential store / elastic potential store / nuclear store / thermal store) → thermal storePrompt: Is it moving, high up, stretched, hot, a fuel or food, or atomic?
2. A ball is thrown straight up. As it rises and slows down, which store increases? (gravitational potential / kinetic / chemical / nuclear) → gravitational potentialPrompt: Its height increases while its speed decreases.
3. Energy stores: which statement is NOT true? (Food contains energy in a chemical store. / Energy cannot be created or destroyed, only transferred between stores. / Energy is measured in joules (J). / Energy is used up when a battery goes flat.) → Energy is used up when a battery goes flat.Prompt: Is light a store or a way of transferring energy?

• Wind up a toy or stretch an elastic band and ask where the energy goes.
• Share the objective: Follow energy transfers and spot wasted energy. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: Every second, an electric fan is supplied with 500 J of energy. 450 J is transferred usefully (movement of the blades). How much energy is wasted each second, in J?
• Step 1: 500 − 450 = 50
• Step 2: So the answer is: 50 J
• Answer: 50 J
• Pause after each step and ask a student to say what comes next.

• Do these together. Students try each step on whiteboards before you reveal it.
• Use the hints as prompts rather than giving the answer.

1. Every second, a drill is supplied with 2000 J of energy. 400 J is transferred usefully (turning the drill bit). How much energy is wasted each second, in J? → 1600 JPrompt: Total energy in = useful energy out + wasted energy out.
2. Some electric cars use regenerative braking. What does this do? (creates new energy from nothing / makes the brakes hotter / transfers kinetic energy back into the battery's chemical store / stops the car using air only) → transfers kinetic energy back into the battery's chemical storePrompt: The motor works as a generator while slowing.

• Students work on the student sheet. Circulate and check the first two answers of every student early.
• Students who finish: write a question of their own for a partner, with the answer.

The 6 questions are on the student sheet below, with answers in the key.

• Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.

1. Every second, an LED lamp is supplied with 2000 J of energy. 200 J is transferred usefully (light). How much energy is wasted each second, in J? → 1800 JPrompt: Total energy in = useful energy out + wasted energy out.
2. Energy transfers: which statement is true? (Lubrication can reduce wasted energy in machines. / Wasted energy is destroyed. / An LED lamp transfers all its energy to light. / Machines can give out more energy than they take in.) → Lubrication can reduce wasted energy in machines.Prompt: Can energy ever be destroyed?

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-6.