• 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 tiny drum / a small drum with a tight skin / a drum with a very tight skin) → a big drum with a loose skinPrompt: Big, loose skins vibrate slowly.
2. Pitch and loudness: which statement is true? (Pitch is how high or low a sound is. / Longer strings make higher notes. / Hitting a drum harder makes a higher note. / Loud sounds always have a high pitch.) → Pitch is how high or low a sound is.Prompt: Pitch is about how fast; loudness is about how big.
3. How can you make a guitar string play a higher note? (make it tighter or shorter / make it longer / make it looser / pluck it more softly) → make it tighter or shorterPrompt: Shorter, tighter strings vibrate faster.

• 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 1000 times in 5 seconds. What is the frequency of the sound, in hertz (Hz)? → 200 HzPrompt: Frequency is the number of waves (vibrations) per second.
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.

• 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. On an oscilloscope, wave C has more waves squeezed into the same width as wave A. How does C sound? (higher pitched / silent / lower pitched / louder only) → higher pitchedPrompt: More waves per second means a higher frequency.
2. A guitar string vibrates 125 times in 0.5 seconds. What is the frequency of the sound, in hertz (Hz)? → 250 HzPrompt: Frequency is the number of waves (vibrations) per second.

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