Math
Decimal Calculator
Add, subtract, multiply, divide, round, convert, and compare decimal numbers — with clear step-by-step working and precision controls.
Decimal Math, Rounding & Conversions
Compute decimal operations, control precision, convert formats, and compare values using tolerance.
Use rounding mode to control how ties (.5) are handled.
Small “floating” differences can appear in computers. If you need a clean practical answer, set decimal places and choose a rounding mode.
Decimal places control digits after the point. Significant figures control meaningful digits from the first non-zero digit.
Decimal → fraction uses a close rational approximation limited by your max denominator, then simplifies.
Tolerance-based comparison is useful for measurements and rounded values where exact equality is unrealistic.