Q. When dividing 100.0 by 4.00, what is the correct answer 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 quantity with the least significant figures. 100.0 has 4 significant figures and 4.00 has 3 significant figures, so the result should have 3 significant figures: 25.0.
Q. When dividing 6.02 by 2.0, how many significant figures should the answer have?
A.1
B.2
C.3
D.4
Solution
The result should have the same number of significant figures as the measurement with the least significant figures, which is 2.0 (1 significant figure).
Q. When dividing 6.022 x 10^23 by 2.0, how many significant figures should the answer have?
A.1
B.2
C.3
D.4
Solution
In division, the result should have the same number of significant figures as the factor with the least significant figures. 6.022 x 10^23 has 4 significant figures and 2.0 has 2 significant figures, so the answer should have 2 significant figures.
Q. When multiplying 2.5 and 3.42, how many significant figures should the result have?
A.2
B.3
C.4
D.5
Solution
The result should have the same number of significant figures as the measurement with the least significant figures, which is 2.5 (2 significant figures).
Q. When multiplying 3.00 and 2.5, how many significant figures should the answer have?
A.2
B.3
C.4
D.5
Solution
In multiplication, the result should have the same number of significant figures as the factor with the least significant figures. 3.00 has 3 significant figures and 2.5 has 2 significant figures, so the answer should have 2 significant figures.
Q. When multiplying 3.00 by 2.5, how many significant figures should the answer have?
A.2
B.3
C.4
D.5
Solution
In multiplication, the result should have the same number of significant figures as the factor with the least significant figures. 3.00 has 3 significant figures and 2.5 has 2 significant figures, so the answer should have 2 significant figures.
Q. When multiplying 3.24 by 2.1, what is the correct number of significant figures in the final answer?
A.4
B.3
C.2
D.1
Solution
In multiplication, the result should have the same number of significant figures as the factor with the least significant figures. 3.24 has 3 significant figures and 2.1 has 2 significant figures, so the answer should have 2 significant figures.
Q. When subtracting 5.678 from 10.0, how should the answer be rounded?
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 answer should be rounded to one decimal place: 4.32 becomes 4.3.
Q. Which of the following is the correct representation of 0.0004500 in scientific notation?
A.4.500 x 10^-4
B.4.5 x 10^-4
C.4.5000 x 10^-4
D.4.5 x 10^-5
Solution
In scientific notation, all non-zero digits and any trailing zeros after the decimal point are significant. Therefore, 0.0004500 is expressed as 4.500 x 10^-4.
