• Quick retrieval from earlier learning (What happens when we heat it?). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. What happens when you heat this: water in a kettle? (boils and turns to steam / melts into a liquid / burst open and puff up / turns brown and crunchy) → boils and turns to steamPrompt: Picture it cooking or warming in the kitchen.
2. Why should you never leave a chocolate bar on a sunny car seat? (It will freeze. / It will turn into a cake. / The heat will melt it. / It will disappear.) → The heat will melt it.Prompt: How warm does a car get in the sun?
3. True or false? Heating water enough makes it boil. (True / False) → TruePrompt: Some heated things melt, some cook. Can they change back?

• Show an ice cube melting and a kettle steaming and ask what is the same and what is different.
• Share the objective: Ice melting race: compare melting times. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: How could you keep an ice cube frozen longest on a picnic?
• Step 1: Shade, insulation and a cool box all slow the warming.
• Step 2: So the answer is: Wrap it in a cloth and keep it in a cool box in the shade.
• Answer: Wrap it in a cloth and keep it in a cool box in the shade.
• 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. Glaciers around the world are melting faster than they did 50 years ago. What does the ice race help explain? (Glaciers are made of wax. / Ice melts faster in the cold. / Ice melts only at night. / Warmer surroundings make ice melt faster.) → Warmer surroundings make ice melt faster.Prompt: Earth's average temperature has been rising.
2. In the ice race, why must every ice cube be the same size? (So they look nice in a row. / Because big ice cubes never melt. / It does not matter at all. / So the only difference is the place, making it a fair test.) → So the only difference is the place, making it a fair test.Prompt: What if one cube was twice as big?

• 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. In the ice race, why must every ice cube be the same size? (It does not matter at all. / Because big ice cubes never melt. / So the only difference is the place, making it a fair test. / So they look nice in a row.) → So the only difference is the place, making it a fair test.Prompt: What if one cube was twice as big?
2. What pattern do the ice race results show? (Ice never melts in sunlight. / Ice melts at the same speed everywhere. / The colder the place, the faster the ice melts. / The warmer the place, the faster the ice melts.) → The warmer the place, the faster the ice melts.Prompt: Compare the sunny windowsill and the fridge.

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