Order of operations

Many teachers do not emphasize “order of operation”, but “order of operations” is very important. Without knowing order of operations well, you do not know how to solve a math problem.

Some examples are given in the following, There are also worksheets for you to work on after you understand the examples.

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

 Worksheets for you to work on