1.8 Negative numbers

Numbers can be positive or negative, i.e. greater than or less than zero. Negative numbers have several uses; for example, to measure temperatures below zero, such as 3°C (‘minus 3 degrees Celsius’). They are also used to represent debts and overdrawn accounts: a bank balance of £84.33 means ‘overdrawn by £84.33’.

Negative numbers are shown on the number line to the left of 0. The animation below shows 8, 7, 6, etc.

The numbers always increase as you move to the right along the number line, wherever you start from. 1 is to the right of 2, so 1 is greater than 2. 1° is warmer than 2° and a bank balance of £1 is more than one of £2 (two pounds overdrawn).