Measure
Capacity
Capacity is the total amount that something can hold. We measure capacity in millilitres and litres.
Millilitres and litres
We measure capacity in millilitres (ml) and litres (L). • Millilitres are used for small amounts, like a teaspoon of medicine (5 ml). • Litres are used for large amounts, like a bucket of water. Always remember: 1 litre is equal to 1000 millilitres.
Useful amounts to know
• A teaspoon holds about 5 ml. • Half a litre is 500 ml. • A quarter of a litre is 250 ml. A bottle that holds half a litre is holding 500 ml.
Reading a jug
A measuring jug has a scale with lines. Read the line that the water reaches. If the water is on the 750 ml mark, the jug holds 750 ml of water.
Comparing capacity
We can compare amounts using <, > and =. • 250 ml < 750 ml. • 1 litre = 1000 ml. • 900 ml > 90 ml.
Worked examples
Changing litres to millilitres
- You have 2 litres.
- 1 litre is 1000 ml.
- So 2 litres = 2 × 1000 = 2000 ml.
Answer: 2 litres = 2000 ml.
Tins that make a litre
- Each tin holds 250 ml.
- Four tins hold 4 × 250 = 1000 ml.
- 1000 ml is the same as 1 litre.
Answer: Four 250 ml tins make 1 litre.
How many days of medicine
- The bottle holds 55 ml.
- Chiwitel takes 5 ml each day.
- Share 55 ml into 5 ml doses: 55 ÷ 5 = 11.
Answer: The medicine lasts 11 days.
The same amount, different jugs
- Jug 1 is marked in millilitres and filled to 500 ml.
- Jug 2 is marked in litres and filled to half a litre.
- 500 ml is the same as half a litre.
Answer: Both jugs hold the same amount of water.
Where you see this in real life
- Measuring 5 ml of medicine with a teaspoon.
- Filling a jug with a litre of juice for a party.
- Reading how much water is in a measuring cylinder.
Key words
- Capacity
- The total amount a container can hold.
- Millilitre (ml)
- A small unit of capacity.
- Litre (L)
- A larger unit of capacity. 1 L = 1000 ml.
- Measuring jug
- A container with a scale for measuring liquids.