11+ Maths Choosing Metric Units Practice
21 October 2026
Choosing the right metric unit
Understanding metric units is key for 11+ Maths. Children are often asked to pick the most suitable metric unit for measuring length, mass, or capacity. This skill helps with real-life problems and builds confidence for the exam.
When to use millimetres, centimetres or metres
For small objects, millimetres or centimetres are best. Metres are more suitable for larger items or distances. Choosing the right unit makes answers clear and avoids confusion.
Key insight: Encourage your child to picture the object and compare it to familiar items. If it fits in a pencil case, centimetres or millimetres work well. If it is as long as a room, metres are more suitable.
Worked example
A parent wants to measure the length of their dining table. The table is about as long as a door.
Step 1: Think about the size. A table is much longer than a pencil but shorter than a football pitch.
Step 2: Would millimetres be sensible? No, the number would be very large and awkward.
Step 3: Would centimetres work? Possible, but the number might still be quite big (for example, 180 cm).
Step 4: Would metres be easiest? Yes, because the table is about 1.8 metres long. This is a simple, clear number.
The correct answer is metres.
Helping your child practise
Use everyday objects at home. Ask your child which metric unit fits best for each one. Start with simple items like books or bottles, then move to larger things such as doors or garden paths.
