Unit Conversion (Year 4)
Convert between metric units of length, mass and capacity.
The questions below are generated to match the National Curriculum for Year 4 and get harder as you progress from Rookie to Guru.
Worked examples
How many minutes is 2 hours and 30 minutes?
- 150 minutes
- 230 minutes
- 2 hours 30 mins
- 120 minutes
Answer: 150 minutes. 2 × 60 + 30 = 150 minutes.
What is the perimeter of a rectangle with length 8 cm and width 5 cm?
- 26 cm
- 28 cm
- 30 cm
- 40 cm
Answer: 26 cm. Perimeter = 2 × (length + width) = 2 × (8 + 5) = 2 × 13 = 26 cm.
Why does the formula A = L × W give cm² as the unit (not cm)?
- Because we multiply length × length — each in cm — and cm × cm = cm² (square centimetres).
- Because the answer is bigger than length.
- Because two-digit numbers always have squared units.
- Because the question said so.
Answer: Because we multiply length × length — each in cm — and cm × cm = cm² (square centimetres).. Multiplying cm × cm gives cm² — square centimetres — because we're measuring area.
Related skills
Frequently asked questions
- What is unit conversion?
- Convert between metric units of length, mass and capacity.
- How can my child practise unit conversion at home?
- Work through the examples below, then start a free adaptive session. Northstar adjusts the difficulty automatically and tracks mastery over time.
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