Numbers can either be positive or negative. Often brackets are put around negative numbers to make them easier to read, e.g. (-2). If a number is positive, the + is usually missed out before the number. So 3 is really (+3). Adding and multiplying combinations of positive and negative numbers can cause confusion and so care must be taken.

**Addition and Subtraction**

Two ‘pluses’ make a plus, two ‘minuses’ make a plus. A plus and a minus make a minus.

*Example*:

3 + (-2)

A plus and a minus make a minus, so this is the same as 3 – 2 = 1

*Example*:

(-2) + (-5) = -7

This is the same as (-2) – 5 = -7

**Multiplication and Division**

If two positive numbers are multiplied together or divided, the answer is positive.

If two negative numbers are multiplied together or divided, the answer is positive.

If a positive and a negative number are multiplied or divided, the answer is negative.

*Examples*:

(-2) ÷ (-4) = ½

(8) ÷ (-2) = (-4)

2 × (-3) = (-6)

(-2) × (-2) = 4