What is BODMAS: Explained For Primary School (With Practice Questions)

BODMAS crops up throughout primary school maths so here we cover what BODMAS means, and provide you with some BODMAS questions and exercises you can use to help any KS2 child practise accurately carrying out BODMAS calculations. 

BODMAS meaning

When presented with a number sentence containing more than one operation (such as 3 + 4 x 2) the operations cannot be completed from left to right, but instead in their order of importance according to the BODMAS rule.

Mathematical operations

Mathematical operations are what you do to the numbers given. The four main operations are:

• addition (+);
• subtraction (-);
• multiplication (x);
• and division (÷).

What does order of operations mean? 

This is the order in which certain operations must be completed, from brackets (also known as parentheses) first to addition and subtraction last.

It is important that division and multiplication are represented alongside each other as they are of equal importance (so must be completed from left to right, whichever appears first) – this is the same for addition and subtraction.

BODMAS examples

Below are some examples of BODMAS questions and answers children might see in real life in schools. We’ve given you the right answer and at least one different answer to show you where children might make a mistake or work through BODMAS in the wrong order.

BODMAS Questions and Answers

Question 1: 6 + 2 x 7

The correct answer is 20.

The multiplication must be completed first (2 x 7 = 14) and then the addition (6 + 14 = 20).

This may be commonly miscalculated as 56 by working from left to right (6 + 2 = 8, 8 x 7 = 56).

Question 2: 3 x (2 + 4) + 5²

The correct answer is 43.

The BODMAS rule states we should calculate the Brackets first (2 + 4 = 6), then the Orders (5² = 25), then any Division or Multiplication (3 x 6 (the answer to the brackets) = 18), and finally any Addition or Subtraction (18 + 25 = 43).

Children can get the wrong answer of 35 by working from left to right.

Question 3: 5 – 2 + 6 ÷ 3

The correct answer is 5.

The division must be completed first (6 ÷ 3 = 2) which then leaves addition and subtraction; as both are of the same importance, we can then work from left to right. 5 – 2 + 2 (the answer to 6 ÷ 3) = 5.

This may be commonly miscalculated as either 3 by working from left to right, or as 1 by wrongly assuming that addition should be completed before subtraction.

When do children learn about BODMAS in primary school?

BODMAS is taught in upper KS2 and often primary school children won’t come across the order of operations until Year 6.

The national curriculum states that Year 6 pupils should be taught to use their knowledge of the order of operations to carry out calculations involving the four operations.

The non-statutory guidance advises that pupils explore the order of operations using brackets; for example, 2 + 1 x 3 = 5 and (2 + 1) x 3 = 9.

BODMAS calculator

Most calculators and computers nowadays are sophisticated enough to complete calculations according to BODMAS. However it’s worth testing any calculator out just to be sure. There are also plenty of BODMAS calculators available online.

Practice KS2 BODMAS questions 

1) 29 – 4 x 6 + 5 =

Answer: 10

2) Write what the two missing numbers could be. (4 + ?) x ? = 100

Answer: 6 and 10 (4 + 6) x 10 = 100

3) Write the missing numbers to make these calculations correct.

a) 200 x ? – 200 = 200

b) (100 – ?) x 100 = 100

Answers:  a) 2     b) 99

4) Write the correct sign >, < or = in each of the following

a) (10 + 5) – 9 [     ] (10 + 9) – 5

b) 3 x (4+5) [     ]  (3 x 4) + 5

c) (10 x 4) / 2 [     ]  10 x (4 / 2)

Answers :

a) (10 + 5) – 9 < (10 + 9) – 5

b) 3 x (4+5) > (3 x 4) + 5

c) (10 x 4) / 2 = 10 x (4 / 2)

Practice Year 6 BODMAS questions