Omni Calculator

Find a topic-specific model, then follow its input definitions. Omni's significant-figures tool accepts a number or arithmetic expression, reports decimal/scientific forms and significant digits, and supplies steps for operations. An optional precision field rounds using half-up rounding. Addition/subtraction follow decimal-place precision; multiplication/division follow significant-digit precision, so those rules are not interchangeable. Mixed operations track precision across steps before final rounding. The guide explains how to enter exact factors with enough digits to avoid treating them as measured limitations. A share-result control is available; the free collection's other scientific and everyday calculators use different assumptions.