3.8 Order of decimal calculations

The same rules about the order of calculations apply to decimals as apply to whole numbers.

Calculations are performed in the following order:

Brackets;

Powers (e.g. squaring or cubing a number);

Division and Multiplication (performed in the order written, left to right);

Addition and Subtraction (performed in the order written, left to right).

Example 19

Calculate 3.5 + 0.7 × 8 ÷ (4.6 − 2.6).

Answer

Brackets first: 4.6 − 2.6 = 2.0, so calculate 3.5 + 0.7 × 8 ÷ 2.0.

Multiply next: 0.7 × 8 = 5.6, so calculate 3.5 + 5.6 ÷ 2.0.

Divide next: 5.6 ÷ 2 = 2.8, so calculate 3.5 + 2.8.

Lastly add: 3.5 + 2.8 = 6.3.

So the answer is 6.3.