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

1. Is this rock permeable or impermeable: marble? (permeable (lets water through) / impermeable (does not let water through)) → impermeable (does not let water through)Prompt: Does water soak in, or run off the surface?
2. How can you test which rock is hardest? (smell them / weigh them / look at their colour / try to scratch each with the same object, such as a steel nail) → try to scratch each with the same object, such as a steel nailPrompt: A harder rock is more difficult to scratch.
3. Rocks and soils: which statement is NOT true? (Rocks can be compared by hardness and permeability. / Soil contains bits of rock and organic matter. / Granite lets water soak through easily. / Rocks can be natural or made by people, like brick and concrete.) → Granite lets water soak through easily.Prompt: What is soil mainly made of?

• Pass round different rocks and ask how each one might have formed.
• Share the objective: Weathering and erosion. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: Which type of weathering is this: rocks heating by day and cooling at night?
• Step 1: Physical weathering breaks rock into pieces without changing what it is made of.
• Step 2: So the answer is: physical weathering
• Answer: physical weathering
• 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. Which type of weathering is this: rabbits burrowing into soft rock? (physical weathering / chemical weathering / biological weathering) → biological weatheringPrompt: Is it caused by temperature and ice, by a chemical reaction, or by living things?
2. What is the difference between weathering and erosion? (Erosion only happens in deserts / Weathering breaks rock down; erosion carries the pieces away / Weathering moves rocks to the sea / They are exactly the same) → Weathering breaks rock down; erosion carries the pieces awayPrompt: One breaks, the other moves.

• 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. Which type of weathering is this: rabbits burrowing into soft rock? (physical weathering / chemical weathering / biological weathering) → biological weatheringPrompt: Is it caused by temperature and ice, by a chemical reaction, or by living things?
2. Which landform is mainly carved by a river over a very long time? (a sand dune / a volcano / an island / a canyon) → a canyonPrompt: The Grand Canyon was cut by the Colorado River.

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-4.