Volume conversion problems involving milliltres and litres.

Millilitres and litres are metric units of volume (capacity). A large carton of milk is approximately the size of 1 litre. In order to convert between litres and millimetres you need to know that there are 1000 millilitres in 1 litre. So if you need to convert a measurement from litres into millilitres then multiply by 1000 and if you need to convert a measurement from millilitres into litres then divide by 1000. It may also be used to remember that 1/4l = 250ml, 1/2l = 500ml and 3/4l = 750ml.

Example 1

Convert 8.7 litres into millilitres.

Since you are converting litres into millilitres you need to multiply the litre amount by 1000:

8.7 x 1000 = 8700ml

Example 2

Convert 4.12 litres into millilitres.

Again, you are being asked to convert a litre amount into millilitres so multiply the litre amount by 1000:

4.12 x 1000 = 4120ml

Example 3

Convert 12000 millilitres into litres.

This time you are converting millilitres into litres so you need to divide by 1000:

12000/1000 = 12 litres.

Example 4

Convert 85 millilitres into litres.

Again, you are converting millilitres into litres so divide by 1000:

85/1000 = 0.085 litres

Example 5

Convert 8 ¾ litres into millilitres.

Again you are converting litres into millilitres.

8 litres is the same as 8000 millilitres (8 x 1000) and ¾ litres is the same as 750 millilitres.

So 8000 + 750 = 8750 milliltres

Example 6

Mark drinks approximately 250ml of milk every day. How much milk will he drink through the whole month of March? Give you answer in litres.

First you need to work out how much milk Mark drinks through the whole of March. Since March has 31 days you need to multiply this by 250:

31 x 250 = 7750ml

So in March Mark drinks 7750 millilitres of milk. You are now required to convert this amount back into litres. You can do this by dividing the amount in millilitres by 1000:

7750/1000 = 7.750 litres.

So he drinks 7.75litres of milk in March.

Example 7

Tony uses approximately 34.7 litres of water every day. How much water does Tony use in one week? Express your answer to the nearest 1000 millilitres.

Since there are seven days in one week you need to multiply 34.7 by 7:

34.7 x 7 = 242.9 litres

To convert this amount into millilitres you need to multiply by 1000:

242.9 x 1000 = 242,900ml

So to the nearest 1000ml your answer is 243,000ml

Summary

1000 millilitres = 1 litre

Converting litres into millilitres multiply by 1000.

Converting millilitres into litres divide by 1000.