• Quick retrieval from earlier learning (Choosing a measuring tool). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. Which tool would you use to measure how hot a cup of tea is? (a stopwatch or timer / weighing scales / a thermometer / a ruler or tape measure) → a thermometerPrompt: Is it a length, a temperature, a mass, a time or an amount of liquid?
2. What could you measure with a thermometer? (the mass of a pumpkin / how much rainwater was collected / the mass of a bag of flour / how cold the water in a pond is) → how cold the water in a pond isPrompt: What does this tool measure: length, temperature, mass, time or volume?
3. Kofi wants to find out which ball bounces highest. Which tool helps most? (a thermometer / a measuring jug / weighing scales / a metre stick (long ruler)) → a metre stick (long ruler)Prompt: Bounce height is a length.

• Show a simple experiment with one thing changed and ask what makes it a fair test.
• Share the objective: Units of measurement. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: What do degrees Celsius (°C) measure?
• Step 1: Degrees Celsius (°C) measure temperature.
• Step 2: So the answer is: temperature
• Answer: temperature
• 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 do hours (h) measure? (length / mass / volume / time) → timePrompt: Think of something you would measure in this unit.
2. Which unit is best for a spoonful of medicine? (kilometres (km) / millilitres (mL) / litres (L) / degrees Celsius (°C)) → millilitres (mL)Prompt: It is a very small amount of liquid.

• 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. What do millimetres (mm) measure? (mass / temperature / time / length) → lengthPrompt: Think of something you would measure in this unit.
2. A runner's time for a race is written as 14.2. Which unit makes sense? (hours (h) / metres (m) / kilograms (kg) / seconds (s)) → seconds (s)Prompt: A short race is over quickly.

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-2.