Unit 2 Practice 3.5
1. Define significant figures. Why are they important?
Because the number of digits used to express a measured or calculated quantity.
2. Explain accuracy and precision.
the closeness of agreement between a measured quantity value and a true quantity value
of a measurand
3. Write the following in scientific notation:
a. 4200. 4.2 x 10³
b. 32400. 32.4 x 10³
c. 201.
2.01 x 10²
d. 0.00506. 5.06 x 10-⁴
e. 0.000871. 8.71 x 10-⁵
4. How many significant figures are in each of the following:
a) 25.45grams. 2
b) 2700mm.
4
c) 35604ml.
5
d) 18000km.
5
e) 0.00533cm.
3
f) 604.0500dl.
5
g) 306mm.
3
h) 0.007800mm. 4
5. Round the following to two significant figures:
a) 2.768cm
b) 6204.5g
c) 0.00004790
d) 0.63704
Unit 2 Practice 3.5
6. Convert the following:
a) 4.4miles=?cm
708111cm. = 710000
b) 3.5pounds=?mg.
1,587,573mg= 1,600,000
c) 374mL=?pints.
0.790403pints=0.80
d) 45m=?yd.
49.2126yd=50
e) 75mi/hr=?cm/minute.
201l25cm/ min = 20,000cm/ min
7. There are 12 eggs in a carton. How many significant figures does the value of 12 have
in this case?
an infinite number of significant figures in 12 eggs