Math Scan Solver Calculator

Use + - * / ^ ( ) and % for remainder. Multiplication and division are done before addition and subtraction. In "words" mode, type the sum in plain English instead.
Exact mode reads every decimal you type as a fraction and works in whole-number numerators and denominators. It cannot use pi, e or functions such as sqrt.
Name a value the expression may use, e.g. "l = 12, w = 7" with an expression of 2 * (l + w).
Changes how the answer is written out. It never changes the arithmetic.
Result
20
Basic Arithmetic Calculator
Unrounded result
20
Expression evaluated
3 * (4 + 5) - 7
Result with separators
20
Result as a fraction
20
Operation
Expression
Arithmetic used
Binary floating point (IEEE-754 double)
Worked out from ISO 80000-2, Quantities and units — Part 2: Mathematics (operator symbols and precedence) and 3 other sources.

How this is worked out

4 steps
  1. Evaluate 3 × (4 + 5) - 7 using standard operator precedence.
  2. 1. [Parentheses → Addition] 4 + 5 = 9 → 3 × 9 - 7
  3. 2. [Multiplication] 3 × 9 = 27 → 27 - 7
  4. 3. [Subtraction] 27 - 7 = 20 → 20
Step-by-step workingtable
1. [Parentheses → Addition] 4 + 5 = 9 → 3 × 9 - 7, 2. [Multiplication] 3 × 9 = 27 → 27 - 7, 3. [Subtraction] 27 - 7 = 20 → 20

Results are general information, not financial, tax, legal, medical or engineering advice.