How to explain measure liquid volumes - metric units in capacity & volume to your child
31 October 2026
Understanding how to measure liquid volumes is a key part of primary maths. Children often see drinks, bottles and recipes using metric units like litres and millilitres. This example question helps your child see how these units work together in a real-life context.
Example question
A bottle contains 1 litre of juice. You pour out 250 millilitres. How much juice is left in the bottle?
Step 1: Understand the units
1 litre (L) = 1000 millilitres (ml). So, 1 litre is the same as 1000 ml.
Step 2: Convert litres to millilitres
1 litre = 1000 ml. The bottle has 1000 ml of juice.
Step 3: Subtract the amount poured out
1000 ml - 250 ml = 750 ml.
Step 4: Convert back to litres if needed
750 ml = 0.75 litres.
Answer:
There are 750 millilitres or 0.75 litres of juice left in the bottle.
After working through this example, your child will recognise how to convert between litres and millilitres and know how to subtract one amount from another. They will be ready to practise similar questions on measuring liquid volumes using metric units.
