PEMDAS is an acronym for the order in which mathematical operations should be performed as you move from left to right through an expression or equation:

You may have had PEMDAS introduced to you as “Please Excuse My Dear Aunt Sally.” Excuse us, but that’s a supremely lame 1950s-style acronym. We prefer, Picking Eminem Made Dre A Star. Whatever. Just remember PEMDAS.

If an equation contains any or all of these PEMDAS elements, first carry out the math within the parentheses, then work out the exponents, then the multiplication, the division, addition, and finally the subtraction.

An example will make this easier to get:

First work out the math in the parentheses (following PEMDAS even within the parentheses—always do multiplication before subtraction):

Now work out the exponents:

Then do the multiplication:

Then the division:

Then the addition:

And, finally, the subtraction: