• Quick retrieval from earlier learning (Heating and cooling: can the change be undone?). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. Can this change be undone: burning a log on a fire? (can change back / cannot change back) → cannot change backPrompt: Could you get the starting material back by warming it or cooling it?
2. Three of these changes CAN be undone. Which one is different? (chocolate melting in a warm hand / butter softening in a warm kitchen / candle wax melting / frying an egg) → frying an eggPrompt: Think about melting and freezing versus cooking and burning.
3. Melted chocolate is poured into a mould and put in the fridge. What happens? (It turns into cake. / It turns into water. / It turns solid again, in the mould's shape. / It stays liquid for ever.) → It turns solid again, in the mould's shape.Prompt: Melting can be reversed by cooling.

• Show an ice cube melting and a kettle steaming and ask what is the same and what is different.
• Share the objective: What happens when we heat it?. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: What happens when you heat this: butter in a hot pan?
• Step 1: So the answer is: melts into a liquid
• Answer: melts into a liquid
• 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. What happens when you heat this: a raw egg in a pan? (burst open and puff up / rises and becomes a spongy solid / turns white and firm / boils and turns to steam) → turns white and firmPrompt: Picture it cooking or warming in the kitchen.
2. Why do cooks put butter in a warm pan before frying? (Heat melts the solid butter so it can spread over the pan. / Heat turns butter into ice. / Butter turns into a gas straight away. / Butter cools the pan.) → Heat melts the solid butter so it can spread over the pan.Prompt: What does heat do to many solids?

• 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 8 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. A clay model is soft. How can you make it hard and strong for good? (Put it in the fridge. / Squash it. / Leave it in water. / Bake (fire) it in a kiln.) → Bake (fire) it in a kiln.Prompt: Bricks and plates are made this way.
2. What happens when you heat this: cake batter in the oven? (melts into a liquid / rises and becomes a spongy solid / turns white and firm / burst open and puff up) → rises and becomes a spongy solidPrompt: Picture it cooking or warming in the kitchen.

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-2.