ISBN-13: 9780132344371 978-0132344371
Clinical Laboratory Mathematics (Ball)
Chapter 3 Rounding and the Significance of Figures
1) Why is a value obtained by measuring something considered inexact?
A) Manufactured tools for measuring objects are all invalid.
B) Measured objects are likely to change over time.
C) The process of measuring can only be accurately performed by machines.
D) There is an inherent uncertainty involved in making measurements.
2) Which of the following is true about exact numbers and inexact numbers?
A) Exact numbers are imprecise, and inexact numbers are precise.
B) Exact numbers are those measured by machines, and inexact numbers are measured by humans.
C) Exact numbers have been confirmed by repeated measurements, and inexact numbers are from a single measurement.
D) Exact numbers result from counting things, and inexact numbers result from measuring things.
3) A scientist measures the volume of a liquid and determines it to be 324 mL. However, for the purposes of her experiment, the value must be rounded to the nearest hundred. Which of the following value should she use?
A) 300 mL
B) 320 mL
C) 330 mL
D) 400 mL
4) Absolute uncertainty represents the raw amount of uncertainty in a measurement. How does relative uncertainty relate to this?
A) Relative uncertainty indicates how much uncertainty is present relative to how much absolute uncertainty could exist.
B) Relative uncertainty is a measure of how accurate the value of the absolute uncertainty is.
C) Relative uncertainty represents the fraction of absolute uncertainty that could impact scientific conclusions.
D) Relative uncertainty tells how large the absolute uncertainty is in relation to the measurement.
5) Two samples are weighed. In which of the following sets of weights would the two results round to the same whole number?
A) 35.12 and 35.67
B) 42.89 and 43.89
C) 51.75 and 52.12
D) 67.41 and 69.01
6) What should be done to the rounding digit if the number to the right of it is less than 5?
A) The digit is decreased by 1.
B) The digit is increased by 1.
C) The digit is rounded up.
D) The digit is not changed.
7) You are given the number 62,359 and asked to round it to the nearest ten. What number would the “5” currently located in the tens column be after rounding?
8) Which statement is accurate regarding the total number of significant figures a number contains?
A) As the number of significant figures increases, the precision of the value increases.
B) In science, a measurement is only considered valid if it contains at least four significant digits.
C) As the number of significant digits increases, so does the margin of error in a measurement.
D) The number of uncertain digits increases as the number of significant digits increases.
9) What is a trailing zero?
A) A zero that is found between two nonzero digits
B) Any zero that is positioned immediately after a decimal point
C) Any zero that follows the last nonzero digit in a number
D) A zero that follows any nonzero digit
10) Which of the following statements is true regarding the use of significant figures in science?
A) All numbers must be rounded so that all digits are considered significant.
B) Any uncertain digits must be clearly documented alongside the measurement.
C) It is customary to report measurements such that only the last digit is uncertain.
D) Measurements must be repeated until no uncertain digits remain.
11) Which of the following zero types is always significant?
A) Embedded zero
B) Leading zero
C) Preceding zero
D) Trailing zero
12) Consider the following measurement.
Is the number above the arrow a significant digit?
A) No, because it is an embedded zero.
B) No, because it is a leading zero
C) Yes, because it is a precise zero.
D) Yes, because it is a trailing zero.
13) What does the exponential term in an exponential expression tell us about the number of significant figures?
A) The exponential term has no information about the number of significant digits in an exponential expression.
B) The number in the exponential term indicates how many zeros must be added to the number of significant figures in the significand.
C) The number in the exponential term must be added to the number of significant figures in the significand.
D) The number of significant figures in the significand must be multiplied by the number in the exponential term.
14) Which of the following numbers contains an embedded zero?
15) A laboratory technician dissolves 5.255 grams of sucrose in water and brings the final volume to 1.0 liter. Which of the following expresses the resulting concentration with the correct number of significant figures?
A) 5 g/L
B) 5.3 g/L
C) 5.23 g/L
D) 5.255 g/L
16) How should the answer for the following calculation based on three measurements be written to account for the number with the highest degree of uncertainty?
10 + 101 + 1111 = 1222
17) What is the rule for determining the number of significant figures to include in the product of a calculation that combines multiplication and subtraction?
A) Apply the rules for figure significance before and after every step involving subtraction.
B) Complete the entire calculation and then round the final answer to have the same number of significant digits as the measurement with the most significant digits.
C) Match the number of significant digits in the operations involving multiplication and division to those involving addition or subtraction after performing the calculation.
D) Round each of the measurements in the calculation to have the same number of significant digits as the measurement with the least before beginning the calculation.