11+ Maths: BIDMAS: Order of Operations
21 October 2026
Understanding BIDMAS for 11+ maths
Getting the order of operations right is essential for 11+ maths. If children do not follow the correct order, their answers can be wrong even if their calculations are accurate. That is why learning BIDMAS is so important.
What does BIDMAS mean
BIDMAS stands for Brackets, Indices, Division and Multiplication, Addition and Subtraction. It tells us the order in which to solve parts of a calculation. Brackets come first, then indices (such as squares or cubes), followed by division and multiplication (from left to right), and finally addition and subtraction (also from left to right).
Worked example
6 + (4 × 3) - 2²
Step 1: Calculate inside the brackets. 4 × 3 = 12
Step 2: Calculate the index. 2² = 4
Step 3: Work through addition and subtraction from left to right. 6 + 12 = 18, then 18 - 4 = 14
The correct answer is 14.
Why order matters
If your child does not use BIDMAS, they might add or subtract before multiplying or dealing with brackets. This leads to mistakes. Practising the correct order helps them solve even complex problems confidently.
Key insight: Practising BIDMAS builds confidence and accuracy for 11+ maths. It helps children avoid common errors and approach each calculation step by step.
Keep practising together
Encourage your child to talk through each step as they solve BIDMAS problems. This habit makes the order of operations second nature and prepares them well for the 11+ exam.
