What is BODMAS?
Year 6 uses the order of operations to carry out calculations with all four operations. Below: what it means, a worked example, the mistake to watch for and an 11+ question.
The answer
BODMAS is the order to do a calculation in: Brackets, then Orders, then Division and Multiplication, then Addition and Subtraction.
What it means
Orders means powers, like ² and ³. Many schools say BIDMAS instead, where I stands for indices. It is the same rule.
Division and multiplication are equal partners: do whichever comes first, working left to right. Addition and subtraction work the same way.
A worked example
Work out 3 + 4 × 2
- Multiplication comes before addition, so work out 4 × 2 = 8 first.
- 3 + 8 = 11. The answer is 11, not 14.
The common mistake
Always doing addition before subtraction because A comes before S. They are equal: work left to right. 20 − 5 + 3 = 15 + 3 = 18, not 20 − 8 = 12.
How it comes up in the 11+
Work out 18 − 6 ÷ 2 + 3 × 4.
Answer: 27
- Division and multiplication first: 6 ÷ 2 = 3 and 3 × 4 = 12.
- That leaves 18 − 3 + 12.
- Left to right: 18 − 3 = 15, then 15 + 12 = 27.
Related words and practice
More maths words
Questions parents ask
What is the difference between BODMAS and BIDMAS?
Nothing but the name. O for orders and I for indices both mean powers, like 3².
Does multiplication always come before division?
No. They have the same priority, so you work left to right. 12 ÷ 3 × 2 = 4 × 2 = 8, not 12 ÷ 6 = 2.
Knowing the words is half of an 11+ maths question
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