• Quick retrieval from earlier learning (How shadows form when light is blocked). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. On a cloudy day with no sunshine, why is it hard to see your shadow? (Shadows only happen at night. / The clouds take your shadow away. / People have no shadows in winter. / The light comes from all over the sky, so it is not blocked in one place.) → The light comes from all over the sky, so it is not blocked in one place.Prompt: A sharp shadow needs light coming from one direction.
2. True or false? Shadows are made of black paint. (True / False) → FalsePrompt: What does an object do to light to make a shadow?
3. Shadows: which statement is true? (A shadow shows your face and your eyes. / The shadow of a cup has the shape of a triangle. / Shadows point towards the light. / A see-through glass makes only a faint shadow.) → A see-through glass makes only a faint shadow.Prompt: Picture a torch, a toy and a wall.

• Ask the class to make a wave with a rope or slinky and describe what moves and what doesn't.
• Share the objective: Clear, cloudy or blocking? How much light gets through. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: How much light passes through this: a thick book?
• Step 1: No light passes through opaque materials, so they make dark shadows.
• Step 2: So the answer is: opaque (lets no light through)
• Answer: opaque (lets no light through)
• 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. How much light passes through this: cling film (plastic wrap)? (transparent (lets almost all light through) / translucent (lets some light through) / opaque (lets no light through)) → transparent (lets almost all light through)Prompt: Hold it up to a window in your mind. Can you see through it?
2. Which of these is opaque? (a clear plastic bottle / clean water / aluminium (aluminum) foil / a clear glass window) → aluminium (aluminum) foilPrompt: Think about the shadow each one would make.

• 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. Why are greenhouses made of clear glass or plastic? (because glass is soft / to keep plants in the dark / to stop rain falling on the roof / so sunlight can reach the plants inside) → so sunlight can reach the plants insidePrompt: What do plants need to make food?
2. Which of these is opaque? (tissue paper / clean water / cling film (plastic wrap) / a brick wall) → a brick wallPrompt: Think about the shadow each one would make.

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-1.