Calculating with Significant Figures (CHEM 1405)

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Calculating with Significant Figures and Scientific Notation

Determine the number of significant figures in each of the following:

_____a.  6.751 m                      ______f.  30.07 mL                    _____k.  54.52 g

_____b.  0.0157 kg                   _____g.  3 x 1034 g                   _____l.  0.1209 mL

_____c.  28.00 L                       _____h.   0.0067 mg                 _____m.  2.6900 kg

_____d.  2500 m                       _____i.  0.0200 cm                    _____n.  43.07 m

_____e.  0.07002 dm                 _____j.  2.60 x 108 m              _____o.  106.  km

 

 

Express each answer using the correct number of significant figures.

Add     

a.  16.5 cm   +   8 cm   +   4.37 cm         =          _____________________

b.  13.25 g   +   10.00 g   +   9.6 g           =          _____________________

c.  4.5 cm   +   375 mm   +   25.9 dm      =          _____________________

 

Subtract

a.  23.27 km   -   12.058 km                   =          _____________________

b.  13.57 g   -   6.3 g                               =          _____________________

c.  5.805 L   -   385.2 mL                        =          _____________________

 

Multiply

a.  2.6 cm  x  3.78 cm                          =          _____________________

b.  6.50 m  x  0.37 m                           =          _____________________

c.  1.4 m  x  8m  x  75.85 m               =          _____________________

 

Divide

a.  35 cm2  /  0.62 cm                            =          _____________________

b.  0.75 g  /  0.003 cm3                          =          _____________________

c.  6.50 m  /  9.2 m                                =          _____________________

 

 

Rank these numbers from smallest to largest using number 1 through 8.

            _____a.  5.3  X  104                               _____e.  0.0057

            _____b.  57  X  103                                _____f.  5.1  X  10-3‑

                _____c.  4.9  X  10-2                              _____g.  0.0072  X  102

            _____d.  6230                                       _____h.  2  X  106

 

 

For the numbers below, change the regular numbers into scientific notation or write as a regular number if already in scientific notation.  Watch out for significant figures.

a.  68902 ____________________            f.  77900.34       _____________________

b.  0.754 ____________________             g.  0.000385      _____________________

c.  248.0 ____________________             h.  4.5  x  103    _____________________

d.  3000 ____________________              i.  8.30  x  102   _____________________

e.  540.0 ____________________             j.  9.080  x  102 _____________________