• Quick retrieval from earlier learning (Find the part that vibrates to make the sound; 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 vibrates to make the sound of a voice? (the stretched skin on top / your vocal cords in your throat / its wings / the metal bell) → your vocal cords in your throatPrompt: Which part moves back and forth when the sound is made?
2. You go into a room with no windows and shut the door. The light is off. What can you see? (only red things / only shiny things / nothing at all / everything, but in black and white) → nothing at allPrompt: What is missing from the room?
3. A ruler is held on a table edge and twanged. How could you see that it is vibrating? (It gets longer. / The free end looks blurry as it moves up and down fast. / It glows. / It turns a different colour.) → The free end looks blurry as it moves up and down fast.Prompt: Look at the end that sticks out.

• Ask the class to make a wave with a rope or slinky and describe what moves and what doesn't.
• Share the objective: Send messages with light and sound. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: Does this signal use light, sound or both: a doorbell?
• Step 1: These signals are heard, so they work even if you cannot see them.
• Step 2: So the answer is: sound
• Answer: sound
• 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. Does this signal use light, sound or both: an ambulance with siren and flashing lights? (light / sound / both light and sound) → both light and soundPrompt: Do you see it, hear it, or both?
2. You are camping in a dark forest and get lost. Which signal could rescuers see from far away? (staying very still in the dark / flashing a torch (flashlight) on and off / whispering / drawing in the dirt) → flashing a torch (flashlight) on and offPrompt: What carries a long way in the dark and is easy to see?

• 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. Ships at sea at night watch for a lighthouse. What message does its light send? (The sea is warm today. / It is time for dinner. / Fish are nearby. / Danger: rocks or land are near here.) → Danger: rocks or land are near here.Prompt: Why would a ship need to know where the coast is?
2. What message does this signal send: a school bell at the end of break? (There may be a fire: get out. / I need help. / Stop and wait. / Playtime is over; go back to class.) → Playtime is over; go back to class.Prompt: Where would you meet this signal, and what should you do?

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