Significant Figures

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2

How many significant figures in each of the following?

1.0070 m 

5 sig figs

17.10 kg 

4 sig figs

100,890 L 

5 sig figs

3.29 x 103 s 

3 sig figs

0.0054 cm 

2 sig figs

3,200,000 

2 sig figs

Slide 12

Rules for Significant Figures in Mathematical Operations

Multiplication and Division: # sig figs in the result equals the number in the least precise measurement used in the calculation.

6.38 x 2.0 =

12.76  13 (2 sig figs)

Slide 13

Sig Fig Practice #2

3.24 m x 7.0 m

Calculation

Calculator says:

Answer

22.68 m2

23 m2

100.0 g ÷ 23.7 cm3

4.219409283 g/cm3

4.22 g/cm3

0.02 cm x 2.371 cm

0.04742 cm2

0.05 cm2

710 m ÷ 3.0 s

236.6666667 m/s

240 m/s

1818.2 lb x 3.23 ft

5872.786 lb·ft

5870 lb·ft

1.030 g ÷ 2.87 mL

2.9561 g/mL

2.96 g/mL

Slide 14

Rules for Significant Figures in Mathematical Operations

Addition and Subtraction: The number of decimal places in the result equals the number of decimal places in the least precise measurement.

6.8 + 11.934 =

18.734  18.7 (3 sig figs)

Slide 15

Sig Fig Practice #3

3.24 m + 7.0 m

Calculation

Calculator says:

Answer

10.24 m

10.2 m

100.0 g - 23.73 g

76.27 g

76.3 g

0.02 cm + 2.371 cm

2.391 cm

2.39 cm

713.1 L - 3.872 L

709.228 L

709.2 L

1818.2 lb + 3.37 lb

1821.57 lb

1821.6 lb

2.030 mL - 1.870 mL

0.16 mL

0.160 mL