Bidmas
BIDMAS: The Order of Operations
Items in this lesson
BIDMAS: The Order of Operations
What do you already know about BIDMAS?
Learning Objective
At the end of the lesson you will be able to use BIDMAS to solve maths problems involving multiple operations and brackets.
Text
What Does BIDMAS Mean?
BIDMAS stands for Brackets, Indices, Division, Multiplication, Addition, Subtraction. It shows us the order to do calculations.
Why Do We Need BIDMAS?
If we don’t follow the correct order, we can get different answers for the same calculation. BIDMAS keeps our answers consistent.
A Real Example
What is 3 + 4 × 2? If you do the addition first, you get 14. If you do the multiplication first, you get 11. BIDMAS tells us to multiply before adding.
Step 1: Brackets
Always start by solving anything inside brackets ( ). Brackets can change the outcome dramatically.
Step 2: Indices
Indices are powers or exponents (like 2²). Always do these after brackets.
Steps 3 & 4: Division and Multiplication
Then do all division and multiplication from left to right. They are equal in priority.
Steps 5 & 6: Addition and Subtraction
Finally, do all addition and subtraction from left to right. They are equal in priority too.
The Full BIDMAS Order
1. Brackets 2. Indices 3. Division 4. Multiplication 5. Addition 6. Subtraction
Division and multiplication are equal. Addition and subtraction are equal. Work left to right within these steps.
Order
Remember
Worked Example: Brackets
Solve: (5 + 3) × 2 Step 1: Brackets: (5 + 3) = 8 Step 2: Multiply: 8 × 2 = 16
Worked Example: Indices
Solve: 2 + 3² Step 1: Indices: 3² = 9 Step 2: Add: 2 + 9 = 11
Test Your Understanding
Try these: 1) 4 + 6 × 3 = ? 2) (5 + 2) × 3 = ? 3) 7² - 8 = ? 4) 12 ÷ 4 + 5 = ?
Challenge Yourself!
Try this tricky one: 2 × (3 + 4²) – 6 ÷ 2 Can you solve it step-by-step using BIDMAS?
Key Takeaways
Always use BIDMAS to work out the correct answer. Follow the order: Brackets, Indices, Division/Multiplication, Addition/Subtraction.
Great Work!
Write down 3 things you learned in this lesson.
Write down 2 things you want to know more about.
Ask 1 question about something you haven't quite understood yet.
