Order of Operations



So that we can more easily write long expressions in math and all solve them the same way, we have a set order that all the operations in the expression must be performed in.  This order is shown in the acronym PEMDAS or the mnemonic ‘Please Excuse My Dear Aunt Sally.’  The initials stand for Parentheses, Exponents, Multiplication, Division, Addition and Subtraction.  One exception to the rule is that multiplication and division must be completed from left to right, even if the division comes before the multiplication.  Here’s an example:


3(5 – 2) + (8 - 4)2


First perform the operations in parentheses:


3(3) + (4)2


Then, the exponents:


3(3) + 16


Then multiplication and division:


9 + 16


Then addition and subtraction: