In school days we have heard something called a BODAMS Rule of Calculation. The Same concept is applied in excel as well.
BODAMS Rule:
B Brackets first
O Orders (i.e Powers and Square Roots, etc.)
DM Division and Multiplication (left-to-right)
AS Addition and Subtraction (left-to-right)
Example: How do you work out 3 + 6 × 2 ?
Multiplication before Addition:
First 6 × 2 = 12, then 3 + 12 = 15
How do you work out (3 + 6) × 2 ?
Brackets first:
First (3 + 6) = 9, then 9 × 2 = 18
How do you work out 12 / 6 × 3 ?
Division and Multiplication rank equally, so just go left to right:
First 12 / 6 = 2, then 2 × 3 = 6
Sometimes you will need to use brackets, (also known as 'braces'), in formula.
This is to ensure that the calculations are performed in the order that you need.
The need for brackets occurs when you mix plus or minus with divide or multiply.
Mathematically speaking the * and / are more important than + and –
The * and / operations will be calculated before + and -
Example 1 : The wrong answer !
You may expect that 10 + 20 would equal 30
And then 30 * 2 would equal 60
But because the * is calculated first Excel sees the
calculation as 20 * 2 resulting in 40
And then 10 + 40 resulting in 50
Example 2 : The correct answer.
By placing brackets around (10+20) Excel performs this part of the calculation first, resulting in 30
Then the 30 is multiplied by 2 resulting in 60.
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