How to explain compare and convert metric units of length in length to your student. Example question
31 October 2026
Children often see lengths written in different metric units, like metres and centimetres. To compare them, it's helpful to change both to the same unit first. This makes it much easier to see which is longer or shorter.
Example question
Compare 3 metres and 250 centimetres. Which is longer?
Step 1: Convert metres to centimetres
1 metre = 100 centimetres
3 metres = 3 × 100 = 300 centimetres
Step 2: Compare the lengths in the same unit
300 centimetres and 250 centimetres
Step 3: Decide which is longer
300 centimetres > 250 centimetres
So, 3 metres is longer than 250 centimetres.
Answer: 3 metres is longer than 250 centimetres.
After working through this example, your child will recognise how to convert between metres and centimetres to compare lengths. They can now try similar questions to build confidence with metric unit conversions.
