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 | 5²– 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 and simplifying
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.
https://youtu.be/w70PyHc4raY
Or, you could join in with the BODMAS Song!
https://youtu.be/Z-FKjqL6NyQ
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 | 5² – 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! | |
AUTHOR, MS. ALISON – PRIMARY MATHS TEACHER.
