Math is all about rules. You can’t go around saying 2 + 3 = 87. You have to follow rules when adding, subtracting, multiplying, dividing, or squaring. The order of mathematical operations is commonly known as PEMDAS. This nifty acronym shows the order in which mathematical operations should be performed as you work through an expression or equation.

There is a small catch to the last two steps of PEMDAS. Once you’re left with addition and subtraction, you move from left to right in the equation.

Let’s take old PEMDAS out for a spin.

First, work out the stuff in the parentheses:

Then do the exponents:

Now multiply like wild dogs are chasing you:

Next, calmly divide anything that needs dividing:

Then do the addition and subtraction, moving from left to right: