In Bodmas we perform equations according to specific rules.

Order of Operations - BODMAS

Operations

"Operations" mean things like add, subtract, multiply, divide, squaring, etc. If it isn't a number it is probably an operation.
But, when you see something like...
7 + (6 × 52 + 3)
... what part should you calculate first? Start at the left and go to the right? Or go from right to left?
Calculate them in the wrong order, and you will get a wrong answer !
So, long ago people agreed to follow rules when doing calculations, and they are:

Order of Operations

Do things in Brackets First. Example:
yes
yes


6 × (5 + 3)

6 × 8
48

no
no


6 × (5 + 3)

30 + 3
33
(wrong)
Exponents (Powers, Roots) before Multiply, Divide, Add or Subtract. Example:
yes
yes


5 × 22

5 × 4
20

no
no


5 × 22

102
100
(wrong)
Multiply or Divide before you Add or Subtract. Example:
yes
yes


2 + 5 × 3

2 + 15
17

no
no


2 + 5 × 3

7 × 3
21
(wrong)
Otherwise just go left to right. Example:
yes
yes


30 ÷ 5 × 3

6 × 3
18

no
no


30 ÷ 5 × 3

30 ÷ 15
2
(wrong)

How Do I Remember It All ... ? BODMAS !



B
Brackets first
O
Orders (ie Powers and Square Roots, etc.)
DM
Division and Multiplication (left-to-right)
AS
Addition and Subtraction (left-to-right)

Divide and Multiply rank equally (and go left to right).
Add and Subtract rank equally (and go left to right)
external image bodmas.gif

After you have done "B" and "O", just go from left to right doing any "D" or "M" as you find them.
Then go from left to right doing any "A" or "S" as you find them.