GoalChoose between millilitres and litres, read container sizes and change litres to millilitres.
New words
liquid volume · how much liquid a container holdsmillilitre (mL) · a small unit for measuring liquid volumelitre (L) · a bigger unit of liquid volume; 1 L is 1,000 mL
Explanation
Liquid volume tells us how much liquid a container holds. We use millilitres (mL) for small amounts: a spoonful of medicine is about 5 mL and a cup of tea is about 200 mL. We use litres (L) for large amounts: a big bottle of water holds 1 L, a bucket holds about 10 L and a car petrol tank holds about 40 L. The two units are connected: 1 L = 1,000 mL. So 2 L = 2,000 mL, and 3,000 mL = 3 L. Four glasses of 250 mL fill 1 L, because 4 × 250 = 1,000. Always write the unit with the number.
Worked examples
Which unit? A spoonful of syrup is a small amount, so we use millilitres. The water in a bath is a large amount, so we use litres.
Litres
Millilitres
1
1,000
2
2,000
3
3,000
5
5,000
Changing litres to millilitres: multiply by 1,000. 1 L = 1,000 mL, 2 L = 2,000 mL, 3 L = 3,000 mL and 5 L = 5,000 mL.
Four glasses of 250 mL fill a 1 L jug: 250 + 250 + 250 + 250 = 1,000 mL, which is 1 L.
Class activity
Kitchen volumes. Find five containers at home and read the volume on each label, such as a bottle of water, a carton of juice or a bottle of cooking oil. Write each volume with its unit. Which are in mL and which are in L? Put them in order from the smallest volume to the largest.
Practice
1
Choose mL or L for each: a cup of tea, a swimming pool, a spoonful of syrup, a water tank on a roof.
A cup of tea: mL. A swimming pool: L. A spoonful of syrup: mL. A water tank: L.
2
How many millilitres are in 3 L?
3 × 1,000 = 3,000 mL.
3
How many litres are in 6,000 mL?
6,000 mL = 6 × 1,000 mL = 6 L.
4
Seif drinks 4 glasses of 200 mL. How many millilitres is that? Is it more or less than 1 L?
4 × 200 = 800 mL. It is less than 1 L, which is 1,000 mL. 1,000 − 800 = 200 mL less.
5
A bucket holds 10 L. Karim fills it with a 500 mL cup. How many cups does he need?
2 cups of 500 mL make 1 L, so 10 L needs 10 × 2 = 20 cups.
