SCIENTIFIC NOTATION, SIGNIFICANT DIGITS AND CONVERSIONS
PRACTICE PROBLEMS
1. How many significant digits are there in each of the following?
a) 146.32 cm
b) 700 m
c) 700.5 m
d) 0.00346 kg
e) 1.00346 kg
f) 3.46 x 10-3 kg
g) 1.38 cm
h) 3.0 x 108 m/s
i) 2640 m/s
j) 2.640 m/s
k) 90027.00 m
l) 0.00730 kg
2. Round off each of the following to two significant digits:
a) 5.934
b) 4.683
c) 76.9
d) 0.34499
e) 0.0181
f) 34611
3. Express the following in scientific notation:
a) 954
b) 321.0
c) 6784
d) 300 000 000
e) 6400
f) 0.0064
g) 0.800
h) 0.00015
i) 0.0285
j) 8630
k) 102
l) 9 000 000 000
4. Expand the following numbers from scientific notation to decimal notation:
a) 3.2 x 105
b) 3.2 x 10-5
c) 3.2 x 100
d) 8.7912 x 102
e) 4.96 x 10-4
f) 3 x 108
g) 3.77 x 105
h) 9.1 x 10-7
i) 9.415 x 104
j) 1.5 x 10-2
k) 6.5 x 10-3
l) 1.783 x 10-1
5. Calculate each of the following. Express each of your answers in the correct number
of decimal places:
a) 21.36 + 2.8 + 35.348 + 2.9164
b) 147.845 – 121.1
c) 143 + 289.25 + 68.45 + 6.00
d) 2.3 x 102 cm + 4.62 x 102 cm + 3.852 x 102 cm
e) 0.005 - 0.0007
f) 7.895 + 3.4
6. Calculate the value of each of the following, expressing your answers in scientific
notation to the correct number of significant digits.
a) (4.0 x 105)(2.0 x 103)
b) 4.0 x 105
2.0 x 103
c) (2.03)2 x 102
d) (5.0 x 4.0)2 x 104
e) 27 x 103
3.0 x 10-4
f) 0.0084 m / 42 m
g) 23.4 x 14
h) 7.895 / 34
i) 0.0945 x 1.47
j) (8.71 x 0.0301) / 0.056
k) (4 x 972) + (76.4 x 29.3) – (12 x 7)
l) (72.67 – 72.63) x (4.2694)
(9.72 + 0.01)
7. Using the factor label method, solve the following problems neatly on a separate
sheet of paper even if you can solve these in your head. The problems get
increasingly difficult. Find the number of:
a) centimetres in 245 metres
b) kilograms in 352 grams
c) minutes in 24 hours
d) metres in 12 kilmetres
e) seconds in an hour
f) grams in 355 milligrams
g) seconds in 4 days
h) days in 10 weeks
i) seconds spent sleeping during a night where you get 8 hours of sleep
8. Use the chart, make the following conversions:
a) 2305 km  m
b) 120 dm  dam
c) 27 cm  mm
d) 3.6 hm  km