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

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 / They are exactly the same / Weathering moves rocks to the sea) → Weathering breaks rock down; erosion carries the pieces awayPrompt: One breaks, the other moves.
3. Which happens quickly rather than over a long time? (a mountain wearing down / a landslide / a canyon forming / a river valley widening) → a landslidePrompt: Some changes to Earth take seconds; others take millions of years.

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

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: Which process is this: tree roots growing into a rock?
• Step 1: Weathering breaks rock into smaller pieces where it is.
• Step 2: So the answer is: weathering (rock breaks down in place)
• Answer: weathering (rock breaks down in place)
• 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 process is this: a river dropping mud at its mouth to make a delta? (weathering (rock breaks down in place) / erosion (pieces are carried away) / deposition (pieces are dropped)) → deposition (pieces are dropped)Prompt: Breaking, moving or dropping?
2. Three of these are examples of erosion. Which one is NOT? (pebbles settling at the bottom of a lake / a river carrying sand downstream / wind blowing soil off a dry field / a glacier scraping rocks along) → pebbles settling at the bottom of a lakePrompt: Is the rock being broken, carried, or dropped?

• 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. Why do roads get more potholes after a cold winter? (Cars are heavier in winter. / Snow eats the road. / Cold makes the road melt. / Water seeps into cracks, freezes, expands and breaks the surface.) → Water seeps into cracks, freezes, expands and breaks the surface.Prompt: What happens to water's size when it freezes?
2. Which process is this: a glacier scraping rocks along? (weathering (rock breaks down in place) / erosion (pieces are carried away) / deposition (pieces are dropped)) → erosion (pieces are carried away)Prompt: Breaking, moving or dropping?

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