Numbers, units and arithmetic
Numbers, units and arithmetic

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Numbers, units and arithmetic

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.

MU120_4M1

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