HOW MANY SIGNIFICANT FIGURES SHOULD BE IN THE ANSWER?

ADDITION AND SUBTRACTION:

Cut off the first column that is not full.

Ex. 25.632  m

         1.48    m

+       2.761  m

       29.873  m

  • The column containing the 3 isn’t complete; therefore, round to 29.87  m
    •

    Ex. 12.476   g

    -        1.21     g

           11.266  g

  • The same holds true for subtraction. Round this answer to the hundredths place since it is the 1st full column from the right = 11.27  g.

    MULTIPLY AND DIVIDE

    Fewest number of sig figs in the given measurements

    EX. (8.000 L) X (0.0217 L) = 0.1736 L2

    The answer should be rounded to 3 sig figs = 0.174L2

    Ex. (12.05L2) / (3.1 L) = 3.887 L

    The answer should be rounded to 2 sig figs = 3.9 L

    Ex. (10.00 g) x (273 g) / (290 g) = 9.41 g

    The answer should be rounded to 2 sig figs = 9.4 g

    WORK THE PROBLEMS AND ROUND THE ANSWERS TO THE CORRECT NUMBER OF SIG FIGS. Be sure to include the unit of measurement.
    1. 61.2 m + 9.35 m + 8.6 m =
    2. 9.44 m + 2.111 m =
    3. 8.3 g x 1.22 g =
    4. (38.742 L2) / (0.421 L) =
    5. 11.365 m + 10.72 m =
    6. 34.61 g – 17.3 g =
    7. 5.40 m x 3.211 m x 1.871 m =
    8. (2.0 m x 39.37 m ) / 2.00 m =