When an expression has more than one operation, the order you work in changes the answer. Math has one agreed-upon order — so everyone gets the same result.
Look at this expression: 2 + 3 × 4. Two students solve it two different ways and get two different answers.
They can't both be right! To avoid arguments like this, mathematicians everywhere agree on one set of rules. By those rules, the answer is 14 — multiplication happens before addition.
Here's the agreed-upon order, from first to last. A common way to remember it is "Please Excuse My Dear Aunt Sally" — PEMDAS.
Do anything inside ( ) first.
Powers like 3² come next.
× and ÷ — working left to right.
+ and − — working left to right.
Multiply and divide are the same step, and add and subtract are the same step. PEMDAS makes it look like multiplication always beats division, but it doesn't — when you have both, you go left to right.
So 12 ÷ 2 × 3 is 6 × 3 = 18, not 12 ÷ 6 = 2. Same idea for adding and subtracting.
An exponent is repeated multiplication: 3² means 3 × 3 = 9. So 2 + 3² becomes 2 + 9 = 11. (We'll dig into exponents more in a later lesson — for now, the activities below focus on the other four operations.)
The trick is to do one operation at a time, always choosing the highest-priority one next. Tap the operation you think comes first. If you're stuck, use the hint.
Sometimes the order gets broken. Look at each worked solution and decide: did they follow the rules, or did they slip up?
Evaluate each expression by following the order of operations. Type the final answer and press Check. You earn a point for each one you get on the first try.