There is a correct order to do calculations in, this is so everyone does calculations in the same way. When we do calculations we need to do them in the correct order.
**The order of operations is:
- Brackets
- Indices
- Dividing and Multiplying
- Adding and Subtracting**
Dividing and Multlipying are in the same line - they can be done in any order.
Adding and Subtracting are also on the same line - they can be done in any order but it is usually easier to do them from left to right.
Example 1:
3 + 5 × 4
We have no brackets and no indices.
We will start with the multiplication
5 × 4 = 20
So we now have 3 + 20
3 + 20 = 23
3 + 5 × 4 = 23
Example 2:
(2 + 7)² - 11
We start with the brackets.
2 + 7 = 9
So we now have 9² - 11
Next is the indices
9² = 81
So now we have 81 - 11
81 - 11 = 70
(2 + 7)² - 11 = 70
Example 3:
30 - 36 ÷ 3 + 5
We have no brackets or indices, so we start with the division
36 ÷ 3 = 12
So we now have 30 - 12 + 5
Next we have the addition and subtraction. It is easiest to do this from left to right (If we did the addition first it would be -12 + 5 = -7).
30 - 12 = 18
18 + 5 = 23
30 - 36 ÷ 3 + 5 = 23
Try these:
