BIDMAS - Order of Operations

Q: Why do we use BIDMAS?

BIDMAS gives you the correct order for solving an expression. To solve expressions correctly, you must follow the BIDMAS sequence: Brackets first, then Indices, then Division and Multiplication, then Addition and Subtraction. Skipping the order can lead you to the wrong answer.

Q: What do you do when there are brackets inside brackets?

Start with the innermost set of brackets and work outwards. Solve what is inside the innermost brackets first, then remove them and move to the next pair. Continue until all brackets are gone, then apply the rest of BIDMAS: Indices, Division and Multiplication, then Addition and Subtraction.

Q: What if my expression only has addition and subtraction?

Work from left to right. Addition and Subtraction sit at the same level in BIDMAS, so you do them in the order they appear in the expression. For example, in "10 minus 6 plus 3", subtract 6 from 10 to get 4, then add 3 to reach 7.

Key concept

BIDMAS tells you the correct order of operations. It stands for Brackets, Indices, Division, Multiplication, Addition, Subtraction. When two operations are on the same level, work from left to right.

BIDMAS - Order of Operations - introduction visual

Video Lesson

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Flashcards

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Total cost of a £300 phone and £20 each for a charger, headphones, and mouse, paid in 12 instalments, as an expression using terms and operators.

Expression (300 + 3 × 20) ÷ 12 with terms and operators labelled, applying BIDMAS to a real-world shopping problem.

Practising BIDMAS with examples such as of division and multiplication, and addition and subtraction.

Step by step example of solving an expression with multiple brackets, 50−(2×(2+4×5)−3), using BIDMAS/BODMAS.

What is a Mathematical Expression?

A mathematical expression is a calculation made using numbers and operations (+, −, ×, ÷).
For example, 3 + 4 × 2 is an expression, but $3 + 4 = 7$ is an equation.

Practice Questions

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Q1Easy

$8 + 4 \times 2 =$ ?

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Interactive Activity

Master the Order of Operations with simple practice

Click the operator to calculate first

BIDMAS Key

B Brackets

I Indices

D Division

M Multiplication

A Addition

S Subtraction

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Students Also Ask

The questions students bump into most on this topic

What does BIDMAS stand for?

BIDMAS stands for Brackets, Indices, Division, Multiplication, Addition, and Subtraction. It tells you the order in which to work through a mathematical expression. You start with Brackets, then handle Indices like powers and roots. Division and Multiplication come next on the same level, followed by Addition and Subtraction.

Why do we use BIDMAS?

BIDMAS gives you the correct order for solving an expression. To solve expressions correctly, you must follow the BIDMAS sequence: Brackets first, then Indices, then Division and Multiplication, then Addition and Subtraction. Skipping the order can lead you to the wrong answer.

Which comes first, division or multiplication?

Neither comes first by default. Division and Multiplication sit at the same level in BIDMAS, so you work through them from left to right in the order they appear in your expression. For example, in "20 divided by 5 times 2", you divide first, then multiply.

What do you do when there are brackets inside brackets?

Start with the innermost set of brackets and work outwards. Solve what is inside the innermost brackets first, then remove them and move to the next pair. Continue until all brackets are gone, then apply the rest of BIDMAS: Indices, Division and Multiplication, then Addition and Subtraction.

What if my expression only has addition and subtraction?

Work from left to right. Addition and Subtraction sit at the same level in BIDMAS, so you do them in the order they appear in the expression. For example, in "10 minus 6 plus 3", subtract 6 from 10 to get 4, then add 3 to reach 7.

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