## significant figures

Measurement and uncertainty The length of the pencil is 15.9\ cm (3 significant figures). Note that the significant figures include the first estimated digit. Example 1 13.5 (3 significant figures) 14 (2 significant figures) 0.0028 (2 significant figures) 0.00280 (3 significant figures) 1500 ??? This value is ambiguous because we do not know whether the last two zeros are being used to locate the decimal point or whether they represent significant figures in the measurement. To remove this ambiguity, it is common to use scientific notation to indicate the number of significant figures. Example 2 1.5 times 10^3 (2 significant figures) 1.500 times 10^3 (4 significant figures) 2.80 times 10^(-3) (3 significant figures)