The agreed order of working out more than one operation is as follows:
Brackets
Powers or Indices
Division and Multiplication
Addition and Subtraction
This can be remembered using the word: BIDMAS
However, remember that multiplication and division are equally important, so in a calculation just involving multiplication and division, carry this out from left to right.
The same is true of addition and subtraction, these two are also equally important, and so we again should carry this out from left to right.
Examples
6 + 9 ÷ 3 = 6 + 3 = 9 (divide first)
(6 + 9) ÷ 3 = 15 ÷ 3 = 5 (brackets first)
15 - 4 × 2 = 15 - 8 = 7 (multiply first)
(15 - 4) × 2 = 11 × 2 = 22 (brackets first)
4 × 32 = 4 × 9 = 36 (power first)
(4 × 3)2 = 122 = 144 (brackets first)
14 - 4 + 5 = 15 (equally important, so left to right)