Evaluate a three-number expression with correct precedence, and compare it to a naive left-to-right reading. Enter the numbers and operations.
Usage Tip
PEMDAS: Parentheses, Exponents, Multiplication/Division, Addition/Subtraction — the last two pairs each share a level and go left to right.
Within the same level, work left to right
Without it, 2 + 3 x 4 would be ambiguous.
The left-to-right column shows what you would get ignoring precedence.
Parentheses are not included here; they would override the order.
The order of operations tells you which calculations to do first: parentheses, then exponents, then multiplication and division from left to right, then addition and subtraction from left to right. This calculator shows the correct result next to a naive left-to-right reading so you can see how much the order matters.
For example, 2 plus 3 times 4 equals 14, not 20, because the multiplication happens before the addition. Many mistakes with calculators and spreadsheets come from forgetting this rule or from missing parentheses. When in doubt, add parentheses to make the intended order explicit, which also makes formulas easier for other people to read.