Converting Imperial and Metric

Converting Imperial and Metric

GCSE(F),

Lengths can be measured in both metric and imperial units. The same applies to mass and volume. Sometimes it is necessary to convert between the two different methods of measurement. The sign means that the answer is approximate.

Length
1 inch (in) ≈ 2.5 centimetres (cm)
1 foot (ft) ≈ 30 centimetres (cm)
1 metre (m) ≈ 39 inches (in)

Mass
1 kilogram (kg) ≈ 2.2 pounds (lb)

Capacity
1 litre (l) ≈ 1.75 pints (pt)
1 gallon (gal) ≈ 4.5 litres (l)

When converting from one set of measurement to another, set up a small table with the conversion factors on the first row and the number to be converted on the second, so that it can be identified whether it is a multiplication or a division that is required.

Examples

1. What is 4 kilograms in pounds?

Answer: 8.8 pounds

kilograms-->pounds
1x2.2
44 x 2.2 = 8.8

2. Jack is having a party. He has made up 14 pints of fruit punch, and will be serving it in 0.5l glasses. How many full glasses of fruit punch will he be able to serve?

Answer: 16 glasses

litres-->pints
1x1.75
14÷1.75 = 814

The glasses are `frac(1)(2)` litre each, so he can serve 16 glasses.