Order of Operations Page 2 of 4
The Order of Operations (PEMDAS)Way back when, mathematicians developed a set of rules to follow for simplifying expressions. They decided that they would all follow the same order to make things easier. If you have an expression with more than one operation, this is the order you need to follow:
An easy way to remember the order is to remember the phrase "Please Excuse My Dear Aunt Sally" or to remember the acronym PEMDAS. There are a couple different ways to describe the order of operations. For example, some teachers might say Brackets instead of Parentheses or Indices instead of Exponents. Don't worry, it's all the same order. Let's look at the steps more closely. Step 1: Parentheses (or other grouping symbols) If there are any operations inside parentheses, do those first. For example, to simplify 3(6  2) you would simplify subtract first since it's inside parentheses and then multiply. Parentheses are just one way to group things together. You might also see brackets like [ ] or { }. Operations inside any of these grouping symbols should be done first. If there are more than one type of parentheses or brackets, simplify what's in the innermost ones first and work your way outside. Step 2: Exponents (or roots) After simplifying operations inside parentheses or brackets, simplify any exponents next. At this step, you also simplify any roots that you may have (for example, a square root). Some teachers, especially in Europe, refer to this step as "Orders." Orders are the same as exponents. You might see the expression BODMAS instead of PEMDAS for the order of operations. This is just because they're calling the steps Brackets and Orders instead of Parentheses and Exponents. Step 3: Multiplication or Division (from left to right) Next, simplify any multiplication or division. If the expression has more than one multiplication or division sign, work your way from left to right. Important Note: Don't assume you multiply first since it's listed first in PEMDAS. Do which ever one comes first from left to right just like how you read a book. In some expressions you'll multiply first and in others you'll need to divide first. Step 4: Addition or Subtraction (from left to right) Last, simplify any addition or subtraction. Just like with the previous step, work your way from left to right. 
