• 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? (People have no shadows in winter. / The light comes from all over the sky, so it is not blocked in one place. / The clouds take your shadow away. / Shadows only happen at night.) → 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? A red ball makes a red shadow. (True / False) → FalsePrompt: What does an object do to light to make a shadow?
3. Shadows: which statement is true? (Shadows point towards the light. / A shadow shows your face and your eyes. / Your shadow moves when you move. / The shadow of a cup has the shape of a triangle.) → Your shadow moves when you move.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: a thick book? (transparent (lets almost all light through) / translucent (lets some light through) / opaque (lets no light through)) → opaque (lets no light through)Prompt: Hold it up to a window in your mind. Can you see through it?
2. Which of these is opaque? (frosted glass in a bathroom window / a clear plastic bottle / a brick wall / a clear glass window) → a brick wallPrompt: 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. Which material is best for curtains that keep a bedroom dark on summer mornings? (frosted glass / thin tissue paper / thick opaque blackout fabric / clear plastic) → thick opaque blackout fabricPrompt: You want to stop all the light.
2. How much light passes through this: a thin cotton sheet? (transparent (lets almost all light through) / translucent (lets some light through) / opaque (lets no light through)) → translucent (lets some light through)Prompt: Hold it up to a window in your mind. Can you see through it?

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