BIDMAS - order of precedence

There is a very specific order in which arithmetic and algebraic expressions must be calculated (many people remember the mnemonic BIDMAS):

• Brackets
• Indexes (I.e. powers - like squared and cubed)
• Division
• Multiplication
• Addition
• Subtraction

If you need to evaluate an expression in a different order, use brackets.

For example, 15 - 2 x 6 = 3

The multiplication must be done before the subtraction. If you need to do the subtraction first, and then multiply the result by 6, you must add brackets:

(15 - 2) x 6 = 78