Order of Operations

When a math problem has more than one step, you need to know what to do first. The order of operations is a set of rules that tells you the right order. It keeps everyone getting the same answer.

The Rules

The rules are often remembered with the word PEMDAS. P is for parentheses, which you do first. E is for exponents. M and D are for multiplication and division, done left to right. A and S are for addition and subtraction, also done left to right.

Some people remember it as Please Excuse My Dear Aunt Sally. This fun sentence helps you remember the order.

Why It Matters

Without the order of operations, the same problem could give different answers. Take 2 + 3 x 4. If you add first, you get 20. If you multiply first, you get 14. The correct answer is 14 because multiplication comes before addition.

Parentheses let you change the order. If the problem is (2 + 3) x 4, you add first to get 5, then multiply to get 20.

Fun Facts

• The order of operations is the same in every country around the world.
• Calculators follow the order of operations automatically.
• Parentheses are the most powerful because they always go first.

Did You Know?

Arguments about the order of operations go viral on social media all the time. People argue about problems like 8 / 2(2+2) because they forget the rules!