What is BODMAS?

BODMAS (or sometimes BIDMAS) is a simple acronym that helps you remember the order in which to solve calculations. Sometimes calculations can get a little more complicated than 2+2! For example, what would you do if you were given a calculation like 3 x (4 x 5²) ÷ 6 + 7 – 8 =?

Don’t Panic! BODMAS is here to help. The acronym itself stands for:

Brackets Orders or

Indices

Division Multiplication Addition Subtraction
Calculations inside brackets always come first This means any indices, powers or roots go next Multiply or divide before you add or subtract. If there is division and multiplication, complete from left to right. Finally, complete any addition and subtraction from left to right.

 

All you needed? Let’s practice BODMAS!


BODMAS Explained

Maths teacher, Alison explains:

BODMAS/BIDMAS is important to remember; if the order is wrong, your answer will be too!

So, let’s calculate the maths problem mentioned above:

3 x (4 x 5²) ÷ 6 + 7 – 8 = ?

Steps:

1.

() Brackets 

Complete the calculation inside the brackets first.

4 x 5² = Work out 5 squared first (Orders)

5² = 25

So 4 x 25 = 100

Our calculation now becomes 3 x 100 ÷ 6 + 7 – 8 = ?

2.

÷× Division and Multiplication 

In this calculation, we have both division and multiplication.

Follow the calculation left to right

3 x 100 = 300

300 ÷ 6 = 50

Our calculation now becomes 50 + 7 – 8 = ?

3.

+- Addition and Subtraction

In this calculation, we have both addition and subtraction.

Follow the calculation left to right

50 + 7 = 57

57 – 8 = 49

Answer: 49!

3 x (4 x 5²) ÷ 6 + 7 – 8 = 49


Easy Ways to Remember BODMAS/BIDMAS

Brackets first then Orders (or sometimes Indices).

Division and/or Multiplication left to right followed by Addition and/or Subtraction left to right.


BODMAS Botch-ups

Here are a few examples of easy mistakes many students make. Can you spot their errors and fix them? Answers at the bottom of the page

Question 1 4 + 3 x 2

= 7 x 2

= 14

Question 2 12 – 4 ÷ 2

= 8 ÷ 2

= 4

Question 3 – 6

= 10 – 6

= 4

Question 4 25 – 6 x 2

6 x 2 = 12

12 – 25 = -13

= -13


Worksheets and Practice


It’s always good to practice your new skills!

Year 6:

Using BIDMAS – Order of operations in calculations 

Year 7:

Using the order of operations in calculations – Worksheet 1 

Using brackets on a calculator

Year 8:

Using brackets in different places for different answers

Using brackets on the calculator to work out combined operations

Multiplying out brackets

Multiplying out brackets and simplifying

Solve equations with brackets

Year 9:

Multiplying out brackets and simplifying

Multiplying out two brackets and simplifying

Using brackets on a calculator


BODMAS Explained in Video and Song

Here is a helpful video to really help you to remember it.

 

Or, you could join in with the BODMAS Song!

 

Answers to BODMAS Botch ups

Question 1 4 + 3 x 2

= 3 x 2 + 4

= 10

The student forgot to multiply first then add, instead they added first then multiplied.
Question 2 12 – 4 ÷ 2

= 4 ÷ 2 = 2

= 12 – 2

= 10

The student forgot to divide first then subtract, instead they subtracted first then divided.
Question 3  – 6

= 25 – 6

= 19

The student doubled the 5 rather than multiplying it by itself.
Question 4 25 – 6 x 2

6 x 2 = 12

12 – 25 = -13

= -13

The student mixed up the subtraction. It should have been 25 – 12 not 12 – 25!

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AUTHOR, MS. ALISON – PRIMARY MATHS TEACHER. 

 

What is Bodmas?