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

1. People in Australia do not fall off the Earth. Why? (Gravity pulls everyone towards the centre of the Earth / They hold on tightly / Australia has no gravity / They wear heavy shoes) → Gravity pulls everyone towards the centre of the EarthPrompt: "Down" means towards the centre of the Earth, wherever you are.
2. Gravity: which statement is true? (Gravity only acts on things that are falling. / Gravity is weaker on the Moon than on Earth. / Heavy objects always fall faster than light ones. / There is no gravity in space.) → Gravity is weaker on the Moon than on Earth.Prompt: What keeps the Moon going round the Earth?
3. Gravity: which statement is NOT true? (Astronauts float in the space station because there is no gravity there. / The Earth's gravity keeps the Moon in orbit. / Gravity is a force that attracts objects with mass towards each other. / Gravity is weaker on the Moon than on Earth.) → Astronauts float in the space station because there is no gravity there.Prompt: Why does the space station stay in orbit?

• Drop a sheet of paper and a scrunched-up sheet together and ask why one falls faster.
• Share the objective: Mass and weight (W = mg). Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: What is the weight of a 75 kg object on Earth? Use g = 9.8 N/kg.
• Step 1: W = 75 × 9.8 = 735
• Step 2: So the answer is: 735 N
• Answer: 735 N
• 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 is the weight of a 8 kg object on Earth? Use g = 9.8 N/kg. → 78.4 NPrompt: weight = mass × gravitational field strength (W = m g)
2. An astronaut's mass is 20 kg. Gravitational field strength on Jupiter is 25 N/kg. What would their weight be there, in N? → 500 NPrompt: Mass stays the same everywhere; weight changes.

• 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. What is the weight of a 12 kg object on Earth? Use g = 9.8 N/kg. → 117.6 NPrompt: weight = mass × gravitational field strength (W = m g)
2. Mass and weight: which statement is NOT true? (Mass is measured in kilograms. / Your mass is the same on the Moon as on Earth. / You would weigh less on the Moon than on Earth. / Weight is measured in kilograms.) → Weight is measured in kilograms.Prompt: Which one changes on the Moon?

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-7.