Order Of Operation Rules

Order of operations rules dictate the order that we add, subtract, multiply and divide in a problem as well as when we work in parentheses and compute using exponents.

The acronym PEMDAS is often used to describe this order.  Some students know this as Please Excuse My Dear Aunt Sally. 
PEMDAS stands for Parentheses, Exponents, Multiplication/Division, Addition/Subtractions.
Given a problem with multiple operations, the rules for order of operations say to do the operations in this order...

Parentheses - Parentheses are often shaped like ( ), but they can also be [ ] or { }.  If there are nested parentheses, then you will need to work the computation(s) in the inner most parentheses first, working your way out.
Exponents - Work exponents next.
Multiplication and Division - As they appear in the problem from left to right.  Be careful here.  It isn't necessarily multiplication then division.
Addition and Subtraction - As they appear in the problem from left to right.

Following this order will always work, but doing one step at a time following this order may not be the most efficient.

This worksheet will walk you through looking at an alternate way to think about longer order of operation problems.  You will want to make certain that the rules about order of operations aren't a problem before you try doing similar problems containing fractions.

 

 

KEY - Order Of Operation Rules

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