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Operations and Calculations - Order of operations (BODMAS/BIDMAS)

Grade 5IGCSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

The order of operations is a standard rule used to clarify which procedures should be performed first in a mathematical expression.

Operations inside Brackets always take top priority and must be solved first.

Indices (or Orders) refer to powers and square roots, which are calculated after brackets.

Multiplication and Division carry equal weight; if both appear, solve them from left to right.

Addition and Subtraction carry equal weight; if both appear, solve them from left to right.

📐Formulae

BIDMAS: Brackets, Indices, Division, Multiplication, Addition, Subtraction

BODMAS: Brackets, Orders, Division, Multiplication, Addition, Subtraction

💡Examples

Problem 1:

7+3×57 + 3 \times 5

Solution:

2222

Explanation:

According to BIDMAS, Multiplication must be done before Addition. Calculate 3×5=153 \times 5 = 15, then 7+15=227 + 15 = 22.

Problem 2:

(10+2)÷31(10 + 2) \div 3 - 1

Solution:

33

Explanation:

Start with Brackets: 10+2=1210 + 2 = 12. Next, perform Division: 12÷3=412 \div 3 = 4. Finally, perform Subtraction: 41=34 - 1 = 3.

Problem 3:

42+8÷24^2 + 8 \div 2

Solution:

2020

Explanation:

First, solve the Indices (Order): 42=164^2 = 16. Next, perform Division: 8÷2=48 \div 2 = 4. Finally, add the results: 16+4=2016 + 4 = 20.

Problem 4:

20÷4×220 \div 4 \times 2

Solution:

1010

Explanation:

Division and Multiplication have equal priority. Solve from left to right: 20÷4=520 \div 4 = 5, then 5×2=105 \times 2 = 10.