Operation Calculator
Perform quick everyday calculations — add, subtract, multiply, and divide two numbers — with all four results shown at once, chaining, and history.
Frequently Asked Questions
What are the four basic arithmetic operations?
Addition (+) combines quantities, subtraction (−) finds the difference, multiplication (×) is repeated addition, and division (÷) splits into equal parts. They come in inverse pairs: subtraction undoes addition, and division undoes multiplication. All of higher mathematics builds on these four operations.
Why is division by zero undefined?
Division asks "how many times does the divisor fit into the dividend?" — and zero fits into any non-zero number infinitely many times, while 0 ÷ 0 could be any value at all. Because no single consistent answer exists, mathematics leaves division by zero undefined, and this calculator flags it rather than returning a misleading result.
What order do operations happen in a longer expression?
The standard order (PEMDAS/BODMAS) is: Parentheses, Exponents, Multiplication and Division (left to right), Addition and Subtraction (left to right). So 2 + 3 × 4 = 14, not 20. This calculator works on one operation at a time — use the "Use result" button to chain calculations in exactly the order you intend.
Why do decimal calculations sometimes show tiny rounding differences?
Computers store numbers in binary, and many decimal fractions (like 0.1) have no exact binary representation — famously, 0.1 + 0.2 = 0.30000000000000004 in raw floating point. This calculator rounds results to 12 significant digits, which removes this artefact for everyday calculations.