Lesson - Order of Operations

Order of Operations


More than one operation may occur in a numerical expression. If the operations were performed in different orders, different answers would result.

For instance, consider 2 + 4 x 5. Different results could occur depending on the order of operations performed.

The Order of Operations is a rule that is applied to ensure that only one answer is possible for a set of operations.

Step 1     Do all operations inside parentheses.

Step 2     Simplify expressions containing exponents.

Step 3     Do multiplication and division as they occur from left to right.

Step 4     Do addition and subtraction as they occur from left to right.


The order is easier to remember if you turn it into an acronym, P E M D A S:

                • Parentheses
                • Exponents
                • Multiplication
                • Division
                • Addition
                • Subtraction


People have also made up a phrase using the first letter of each word:

"Please Excuse My Dear Aunt Sally" 




Answer Key

1.) 3

2.) 7

3.) 4

4.) 6