Conversion is changing a number from one unit of measure to another unit of measure.

We tend to use conversions to make it easier to compare different values and also when we’re trying to add and subtract values of different unit of measure.

In order to change one unit of measure into another one, we need to know how much of the smaller one goes into the bigger one e.g. there are 100 centimetres in a metre and 60 minutes in an hour.


  • Money – changing pounds into pence.
  • Weight – changing kilograms into stone.
  • Length – changing centimetres to metres.
  • Time – changing minutes into hours.

Converting metric units of length

The most common metric units conversions of length are:

  • 1km=1000m
  • 1m=100cm
  • 1cm=10mm
  • 1m=1,000mm