Order of Operations

Order of operations ( in order to make the explanation easy to understand, simple numbers are used)

Without any other operations in an expression: Addition and subtraction are equal operations in the way that is “first come, first served” from left to right:

12+3-9-5

=15-9-5

=6-5

=1

Without any other operations in an expression: multiplication and division are equal operations in the way that is “first come, first served” from left to right:

12 ÷6×3

= 2 ×3

=6

 

When an expression has addition and (or) subtractions with multiplication and (or) divisions in it, multiplications and ( or divisions) should be done first; additions and (or) subtractions should be done afterwards.

 34- 9×3

=34- 27

=7

 

2+ 4 ×5 – 3×7

=2+ 20- 21

=22-21

=1

 

When an expression has parenthesis first, the operations in the parenthesis should be done first and other operations need to follow the rules above.

2+ 4 × (5 – 3) ×7 (operation in the parenthesis is done first)

=2+4 × 2×7 (multiplication is done before addition)

=2+ 8 × 7 (first multiplication is done , now let’s do the second multiplication)

=2+56

=58