• Quick retrieval from earlier learning (Pitch and loudness; Parts of a wave). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. Which drum makes the lowest sound? (a big drum with a loose skin / a small drum with a tight skin / a drum with a very tight skin / a tiny drum) → a big drum with a loose skinPrompt: Big, loose skins vibrate slowly.
2. Pitch and loudness: which statement is true? (Loud sounds always have a high pitch. / Hitting a drum harder makes a higher note. / Longer strings make higher notes. / Sounds get quieter the further you are from the source.) → Sounds get quieter the further you are from the source.Prompt: Pitch is about how fast; loudness is about how big.
3. Water is poured into identical glass bottles to different levels. You blow across the tops. Which bottle gives the highest note? (they are all the same / the empty one / the one with the least water / the one with the most water (shortest air column)) → the one with the most water (shortest air column)Prompt: When you blow, the air inside vibrates.

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

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: A guitar string vibrates 400 times in 4 seconds. What is the frequency of the sound, in hertz (Hz)?
• Step 1: 400 ÷ 4 = 100
• Step 2: So the answer is: 100 Hz
• Answer: 100 Hz
• 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. A guitar string vibrates 1250 times in 5 seconds. What is the frequency of the sound, in hertz (Hz)? → 250 HzPrompt: Frequency is the number of waves (vibrations) per second.
2. A dog whistle produces sound at 25 kHz. What is this frequency in Hz? (1 kHz = 1000 Hz) → 25000 HzPrompt: “kilo” means one thousand.

• 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. On an oscilloscope, wave C has more waves squeezed into the same width as wave A. How does C sound? (louder only / lower pitched / higher pitched / silent) → higher pitchedPrompt: More waves per second means a higher frequency.
2. A dog whistle produces sound at 5 kHz. What is this frequency in Hz? (1 kHz = 1000 Hz) → 5000 HzPrompt: “kilo” means one thousand.

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-6.