Whichever word you prefer, they all describe the correct order of carrying out calculations, often referred to as "The Order of Operations". If you think that you already understand how the system works then you can test and practise your understanding in the KS3 quiz below. If you are unsure then visit the page at BODMAS Detailed Explanation

Here is a quick refresher course of the key elements:

In algebra, letters are often used to represent numbers. But BODMAS is an acronym. Each letter represents a word describing a function. Let's see what they stand for:

- B is for Brackets. If part of the calculation is in brackets, work it out first
- O is for Orders. These are squares, cubes or any other powers. Work these out next
- DM is for Division and Multiplication. These have the same priority so work them out from left to right
- AS is for Addition and Subtraction. These are the last you should do. Like DM, work out AS from left to right.

So, the O in BODMAS stands for Orders. What does the I in BIDMAS represent? Well, it stands for Indices. Orders and Indices mean the same thing. The rules of BODMAS (otherwise known as BIDMAS) are fairly easy to remember but all too easy to forget!

Take your time and carefully read each question. If you get stuck, come back to this introduction to refamiliarise yourself with the correct order. Good luck!

1.

What is the value of 3x^{2} when x = 2?

3

6

9

12

3 x (2 x 2)

2.

What is the correct sequence for mathematical operations?

Addition, Brackets, Division, Order, Multiplication, Subtraction

Brackets, Division, Addition, Order, Multiplication, Subtraction

Brackets, Order, Division, Multiplication, Addition, Subtraction

Subtraction, Addition, Multiplication, Division, Order, Brackets

They don't call it BODMAS for nothing!

3.

What is the value of 2 x 3 + 5?

10

11

15

16

Work out the multiplication sign BEFORE the addition sign

4.

What is the value of (3x)^{2} when x = 2?

6

12

36

48

(3 x 2)(3 x 2)

5.

If x = 5, which of these calculations is correct?

6 + x + 7 - 3 + x - 2 = 24

6x + 7 - (3x - 2) = 24

(6x + 7) (3x - 2) = 24

6x + 7 - 3x - 2 = 24

30 + 7 - 13

6.

What is the value of x^{3} / (4y - 7), when x = 5 and y = 8?

3

4

5

6

125 / 25

7.

What is the value of 2a^{3} - a, when a = 4?

118

120

122

124

(2 x 64) - 4

8.

What is the value of 2 + 3 x 5?

10

15

17

25

Work out the multiplication sign BEFORE the addition sign

9.

What is the value of (3 + a)(4 + a) when a = 4?

56

65

86

68

7 x 8

10.

What does the O stand for in BODMAS?

Odd numbers

Organise

Order

Onion

Orders are squares, cubes or any other powers