Rule | Examples |
Zeros between other nonzero digits are significant | 50.3 meters has three sig figs 3.0025 seconds has five sig figs |
Zeros in front of nonzero digits are not significant. | 0.982 kg has three sig figs 0.0008 seconds has one sig fig |
Zeros that are at the end of a number and also to the right of the decimal are significant. | 57.00 grams has four sig figs 2.000 000 kg has seven sig figs |
Zeros at the end of a number but to the left of a decimal are significant if they have been measured or are the first estimated digit; otherwise they are not significant. | 1000 meters may contain from one to four sig figs, depending on the precision of the measurement 20 meters may contain one or two sig figs |
Type of Calculation | Rule | Examples |
Addition or Subtraction | The final answer should have the same number of digits to the right of the decimal as the measurement with the smallest number of digits to the right of the decimal. |
97.3 + 5.85 103.15 --->(round off) 103.2 |
Multiplication or Division | The final answer has the same number of sig figs as the measurement having the smallest number of sig figs. |
123 x 5.35 658.05 ---> (round off) 658 |