Significant Figures Practice
Count the significant figures or round to the specified number of sig figs.
Common Questions
What are significant figures?
Significant figures (sig figs) are the digits in a measurement that carry meaning about its precision. They include all certain digits plus one estimated digit.
What are the rules for counting significant figures?
All nonzero digits are significant. Zeros between nonzero digits are significant (trapped zeros). Leading zeros are never significant. Trailing zeros after a decimal point are significant. Trailing zeros without a decimal point are ambiguous.
How do you round to the correct number of significant figures?
For multiplication/division: round the answer to the fewest sig figs among the inputs. For addition/subtraction: round to the fewest decimal places among the inputs.
Are exact numbers affected by significant figures?
No. Exact numbers (counting numbers, defined conversions like 1 m = 100 cm) have infinite significant figures and never limit the precision of a calculation.