# Significant Figures Calculator

> Perform arithmetic and round the result using significant-figure rules.

Page: https://askcalculators.com/calculator/significant-figures-calculator/
Definition: https://askcalculators.com/calculator/significant-figures-calculator/definition.json
JSON Schema: https://askcalculators.com/calculator/significant-figures-calculator/schema.json
Version: 1.0.0
Maintained by: AskCalculators (software project; not a credentialed reviewer)
Qualified review: pending. Automated checks do not establish professional approval.
Page status: Live
Review status: Pending

## Use
Open the calculator page and enter values. Query-string parameters can restore and bookmark a calculation.
Example: https://askcalculators.com/calculator/significant-figures-calculator/?operation=multiply&valueA=12.30&valueB=4.5

## Inputs
- operation: Operation; type=select; required; default=multiply; values=add|subtract|multiply|divide
- valueA: First measured value; type=text; required; default=12.30
- valueB: Second measured value; type=text; required; default=4.5

## Outputs
- roundedResult: Result with significant-figure rule; format=text; primary
- unroundedResult: Unrounded numeric result; format=number
- rule: Rule applied; format=text
- retainedDigits: Retained significant figures; format=integer

## Formula
multiplication/division retain the fewest significant figures; addition/subtraction retain the fewest decimal places

## Rules
- Empty optional inputs are undefined, not zero.
- Hidden conditional inputs are ignored.
- Do not invent missing required inputs.