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:
People have also made up a phrase using the first letter of each word:
"Please Excuse My Dear Aunt Sally"