• Quick retrieval from earlier learning (Why we need light to see things). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. What does a torch (flashlight) do in a dark cave? (It gives out light that bounces off the walls so we can see them. / It makes the cave warmer, so we see better. / It makes our eyes stronger. / It makes the walls give out light.) → It gives out light that bounces off the walls so we can see them.Prompt: Where does the light start, and where does it end up?
2. True or false? Dark means there is no light, or very little light. (True / False) → TruePrompt: Where does the light start, and where must it end?
3. Why can you see a book on your desk? (The book makes its own light. / Your eyes send out light onto the book. / Books glow in the dark. / Light from a lamp or the Sun bounces off the book into your eyes.) → Light from a lamp or the Sun bounces off the book into your eyes.Prompt: Does a book give out its own light?

• Ask the class to make a wave with a rope or slinky and describe what moves and what doesn't.
• Share the objective: How we see: light, pupil, lens, retina and brain. 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 job of the pupil?
• Step 1: So the answer is: the hole that lets light into the eye
• Answer: the hole that lets light into the eye
• 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 job of the lens? (the hole that lets light into the eye / the coloured ring that makes the pupil bigger or smaller / focuses light onto the back of the eye / the layer at the back that senses light) → focuses light onto the back of the eyePrompt: Follow the light's path from the front of the eye to the brain.
2. Which part of your body actually makes sense of what your eyes detect? (the brain / the eyelashes / the nose / the pupil) → the brainPrompt: The eye sends signals along a nerve. Where to?

• 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. You walk from a dark room into bright sunshine. What happens to your pupils? (They stay the same. / They get bigger. / They close completely. / They get smaller to let in less light.) → They get smaller to let in less light.Prompt: Too much light can dazzle you.
2. What is the job of the iris? (the coloured ring that makes the pupil bigger or smaller / protects the eye and spreads tears / the hole that lets light into the eye / the layer at the back that senses light) → the coloured ring that makes the pupil bigger or smallerPrompt: Follow the light's path from the front of the eye to the brain.

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