Learn what grouping and exponents do first. PEMDAS is a memory aid for the standard order, not a substitute for reading the expression carefully.

Math as a Language: Symbols With Shared Rules

Symbols and order-of-operation rules keep everyone reading the same expression the same way.

Grammar

Work inside parentheses first, then exponents, then multiply and divide left to right, then add and subtract left to right. That order is agreed convention so 3 + 4 × 2 is 11, not 14.

Example

“Half of eight plus four” can be (8/2) + 4 = 8 or 8/(2+4) depending on grouping. Math uses parentheses so the writer picks which one.

Same number, two looks

Mistakes

Reading left to right and ignoring order of operations.
Using a symbol without saying what it stands for.

Use the calculator

FRACTION CALCULATOROpen calculator →

PERCENTAGE CALCULATOROpen calculator →

FAQ

Do I need PEMDAS?: Learn what grouping and exponents do first. PEMDAS is a memory aid for the standard order, not a substitute for reading the expression carefully.