12) Express the result of the following calculation to the proper number of significant figures:
50.19 – 7966 × 10-3.
13) What is the result, expressed to the proper number of significant figures, of adding 23.4 to
91.237 and then subtracting 23.4?
A) 91.237
B) 91.2
C) 91.3
D) 91.0
E) 91
14) Express the result of the following calculation, in scientific notation, to the proper number of
significant figures: + 19
15) Add the following lengths, each obtained from a different measuring instrument, and round
the answer to the proper number of significant figures: 20.02 m, 5.91 m, 0.0097 m, and 2.467 m.
16) The last page of a book is numbered 764. The book is 3.0 cm thick, not including its covers.
What is the average thickness (in centimeters) of a page in the book, rounded to the proper
number of significant figures?
A) 0.0039 cm
B) 0.072 cm
C) 0.0079 cm
D) 0.00393 cm
E) 0.00785 cm
17) The length and width of a rectangle are 1.125 m and 0.606 m, respectively. You calculate the
rectangle’s perimeter by adding these numbers and multiplying by two. Your calculator’s display
reads 3.462. To the correct number of significant figures, the perimeter should be written as
A) 3.5 m.
B) 3.46 m.
C) 3.462 m.
D) 3.4620 m.