In this worksheet, remember that milli means 1000th and centi means 100th.
Also, kilo means 1000.

This means that:
1 mm = 0.001 m
1 ml = 0.001 l
1 mg = 0.001 g
1 cm = 0.01 m
1 cl = 0.01 l
1 g = 0.001 kg
When problems involve mixed units of measurement, always convert them to work in just one unit.
Often it is easier to work with the smaller unit of measurement and then convert back at the end if the question asks for the answer in the larger unit of measurement.
Example 1
Jack pours out 2 litres of water into a pan and then removes 32 ml.
How much is left in the pan, in litres?
Answer
Work in millilitres.
2000 ml  32 ml = 1968 ml
Convert back to litres by dividing by 1000.
1.968 l is left in the pan.
Example 2
Ann joins a 52 cm pipe, end to end, to one that is 2.5 m long.
How long are both pipes together in m?
Answer
Work in cm.
52 cm + 250 cm = 302 cm
Convert back to m by dividing by 100.
The pipe is 3.02 m long.