Q. What is the result of 5.00 - 2.1, considering significant figures?
A.2.90
B.2.9
C.2.8
D.2.80
Solution
When subtracting, the result should be rounded to the least number of decimal places. 5.00 has two decimal places and 2.1 has one, so the result should be rounded to one decimal place: 5.00 - 2.1 = 2.90 becomes 2.9.
Q. What is the result of adding 12.11 and 0.3, considering significant figures?
A.12.41
B.12.4
C.12.5
D.12.3
Solution
When adding, the result should be rounded to the least number of decimal places. 12.11 has two decimal places and 0.3 has one, so the result should be rounded to one decimal place: 12.41 becomes 12.4.
Q. What is the result of dividing 100.0 by 4.00, considering significant figures?
A.25.0
B.25
C.25.00
D.24.99
Solution
In division, the result should have the same number of significant figures as the measurement with the least significant figures. 100.0 has 4 significant figures and 4.00 has 3 significant figures, so the answer should be 25.0 with 3 significant figures.
Q. What is the result of dividing 6.38 by 2.0, considering significant figures?
A.3.19
B.3.2
C.3.0
D.3.5
Solution
In division, the result should have the same number of significant figures as the measurement with the least significant figures. 6.38 has 3 significant figures and 2.0 has 2 significant figures, so the answer should be rounded to 2 significant figures: 3.19 becomes 3.2.
Q. What is the result of dividing 8.0 by 2.00, considering significant figures?
A.4.0
B.4
C.4.00
D.4.000
Solution
In division, the result should have the same number of significant figures as the measurement with the least significant figures. 8.0 has 2 significant figures and 2.00 has 3 significant figures, so the answer should be 4.0 (2 significant figures).
Q. What is the result of multiplying 6.02 x 10^23 by 3.0, considering significant figures?
A.1.8 x 10^24
B.1.806 x 10^24
C.1.80 x 10^24
D.1.8060 x 10^24
Solution
In multiplication, the result should have the same number of significant figures as the factor with the least significant figures. 6.02 x 10^23 has 3 significant figures and 3.0 has 2, so the answer should be 1.8 x 10^24.
Q. What is the result of subtracting 5.00 from 10.0, considering significant figures?
A.5.0
B.5
C.5.00
D.5.000
Solution
In subtraction, the result should be rounded to the least number of decimal places. 10.0 has one decimal place and 5.00 has two, so the result should be rounded to one decimal place: 5.0.
Q. What is the result of subtracting 5.678 from 10.0, considering significant figures?
A.4.32
B.4.3
C.4.4
D.4.00
Solution
In subtraction, the result should be rounded to the least number of decimal places. 10.0 has one decimal place and 5.678 has three, so the result should be rounded to one decimal place: 4.32 becomes 4.3.