CALCULATION OF DRUG DOSAGES: A WORK TEXT
12TH EDITION
AUTHOR(S)SHEILA J. OGDEN; LINDA FLUHARTY
CHAPTER 1: FRACTIONS PRETEST
CALCULATION OF DRUG DOSAGES — 12TH EDITION
20 ORIGINAL DOSAGE-CALCULATION PRACTICE QUESTIONS
QUESTION 1
Category: [Basic Mathematics]
Difficulty: Foundational
Question:
A nursing student is reviewing fractions before beginning medication-calculation
problems. Which fraction is equivalent to 3/4?
A. 6/12
B. 9/12
C. 12/20
D. 15/24
Correct Answer: B. 9/12
Calculation / Reasoning:
Multiply both numerator and denominator by the same number:
3/4 × 3/3 = 9/12
Because multiplying both parts of a fraction by the same nonzero number preserves its
value, 9/12 is equivalent to 3/4.
Rationale:
1
,Equivalent fractions represent the same quantity even though they have different
numerators and denominators. Multiplying both numerator and denominator of 3/4 by 3
produces 9/12. Option A equals 1/2, option C equals 3/5, and option D equals 5/8.
Recognizing equivalent fractions is important because dosage calculations frequently
require fractions to be converted into forms that can be compared or combined.
Why the other options are incorrect:
A. 6/12 simplifies to 1/2.
B. Correct. 9/12 simplifies to 3/4.
C. 12/20 simplifies to 3/5.
D. 15/24 simplifies to 5/8.
Clinical Focus:
Equivalent fractions may look different but represent the same quantity.
QUESTION 2
Category: [Conversions]
Difficulty: Foundational
Question:
A medication-calculation worksheet contains the fraction 8/12. Which is the fraction in
lowest terms?
A. 2/3
B. 3/4
C. 4/6
D. 6/9
Correct Answer: A. 2/3
Calculation / Reasoning:
The greatest common factor of 8 and 12 is 4.
8÷4=2
12 ÷ 4 = 3
Therefore:
8/12 = 2/3
Rationale:
2
,A fraction is in lowest terms when the numerator and denominator have no common
factor other than 1. Dividing both 8 and 12 by their greatest common factor, 4, gives 2/3.
Although 4/6 and 6/9 are also equivalent to 2/3, they are not fully reduced.
Why the other options are incorrect:
A. Correct; 8/12 reduces to 2/3.
B. 3/4 is not equivalent to 8/12.
C. 4/6 is equivalent to 8/12 but is not in lowest terms.
D. 6/9 is equivalent to 8/12 but is not in lowest terms.
Clinical Focus:
Reduce fractions completely when the calculation requires a simplified result.
QUESTION 3
Category: [Basic Mathematics]
Difficulty: Foundational
Question:
Which fraction is the largest?
A. 1/2
B. 3/8
C. 5/8
D. 7/16
Correct Answer: C. 5/8
Calculation / Reasoning:
Convert the fractions to a common denominator of 16:
1/2 = 8/16
3/8 = 6/16
5/8 = 10/16
7/16 = 7/16
The largest numerator is 10.
Therefore, 5/8 is the largest fraction.
Rationale:
3
, Fractions should be converted to a common denominator when their relative sizes are
not immediately obvious. Once all fractions have denominator 16, comparison is
straightforward. The values are 8/16, 6/16, 10/16, and 7/16. Therefore, 5/8 represents
the greatest amount.
Why the other options are incorrect:
A. 1/2 = 8/16, which is less than 10/16.
B. 3/8 = 6/16, which is less than 10/16.
C. Correct; 5/8 = 10/16.
D. 7/16 is less than 10/16.
Clinical Focus:
Accurately comparing fractions can prevent selecting an incorrect medication amount.
QUESTION 4
Category: [Basic Mathematics]
Difficulty: Moderate
Question:
A student needs to calculate:
2/3 + 1/6
What is the correct answer?
A. 3/9
B. 1/2
C. 5/6
D. 3/6
Correct Answer: C. 5/6
Calculation / Reasoning:
Find a common denominator:
2/3 = 4/6
Then:
4/6 + 1/6 = 5/6
Rationale:
4
12TH EDITION
AUTHOR(S)SHEILA J. OGDEN; LINDA FLUHARTY
CHAPTER 1: FRACTIONS PRETEST
CALCULATION OF DRUG DOSAGES — 12TH EDITION
20 ORIGINAL DOSAGE-CALCULATION PRACTICE QUESTIONS
QUESTION 1
Category: [Basic Mathematics]
Difficulty: Foundational
Question:
A nursing student is reviewing fractions before beginning medication-calculation
problems. Which fraction is equivalent to 3/4?
A. 6/12
B. 9/12
C. 12/20
D. 15/24
Correct Answer: B. 9/12
Calculation / Reasoning:
Multiply both numerator and denominator by the same number:
3/4 × 3/3 = 9/12
Because multiplying both parts of a fraction by the same nonzero number preserves its
value, 9/12 is equivalent to 3/4.
Rationale:
1
,Equivalent fractions represent the same quantity even though they have different
numerators and denominators. Multiplying both numerator and denominator of 3/4 by 3
produces 9/12. Option A equals 1/2, option C equals 3/5, and option D equals 5/8.
Recognizing equivalent fractions is important because dosage calculations frequently
require fractions to be converted into forms that can be compared or combined.
Why the other options are incorrect:
A. 6/12 simplifies to 1/2.
B. Correct. 9/12 simplifies to 3/4.
C. 12/20 simplifies to 3/5.
D. 15/24 simplifies to 5/8.
Clinical Focus:
Equivalent fractions may look different but represent the same quantity.
QUESTION 2
Category: [Conversions]
Difficulty: Foundational
Question:
A medication-calculation worksheet contains the fraction 8/12. Which is the fraction in
lowest terms?
A. 2/3
B. 3/4
C. 4/6
D. 6/9
Correct Answer: A. 2/3
Calculation / Reasoning:
The greatest common factor of 8 and 12 is 4.
8÷4=2
12 ÷ 4 = 3
Therefore:
8/12 = 2/3
Rationale:
2
,A fraction is in lowest terms when the numerator and denominator have no common
factor other than 1. Dividing both 8 and 12 by their greatest common factor, 4, gives 2/3.
Although 4/6 and 6/9 are also equivalent to 2/3, they are not fully reduced.
Why the other options are incorrect:
A. Correct; 8/12 reduces to 2/3.
B. 3/4 is not equivalent to 8/12.
C. 4/6 is equivalent to 8/12 but is not in lowest terms.
D. 6/9 is equivalent to 8/12 but is not in lowest terms.
Clinical Focus:
Reduce fractions completely when the calculation requires a simplified result.
QUESTION 3
Category: [Basic Mathematics]
Difficulty: Foundational
Question:
Which fraction is the largest?
A. 1/2
B. 3/8
C. 5/8
D. 7/16
Correct Answer: C. 5/8
Calculation / Reasoning:
Convert the fractions to a common denominator of 16:
1/2 = 8/16
3/8 = 6/16
5/8 = 10/16
7/16 = 7/16
The largest numerator is 10.
Therefore, 5/8 is the largest fraction.
Rationale:
3
, Fractions should be converted to a common denominator when their relative sizes are
not immediately obvious. Once all fractions have denominator 16, comparison is
straightforward. The values are 8/16, 6/16, 10/16, and 7/16. Therefore, 5/8 represents
the greatest amount.
Why the other options are incorrect:
A. 1/2 = 8/16, which is less than 10/16.
B. 3/8 = 6/16, which is less than 10/16.
C. Correct; 5/8 = 10/16.
D. 7/16 is less than 10/16.
Clinical Focus:
Accurately comparing fractions can prevent selecting an incorrect medication amount.
QUESTION 4
Category: [Basic Mathematics]
Difficulty: Moderate
Question:
A student needs to calculate:
2/3 + 1/6
What is the correct answer?
A. 3/9
B. 1/2
C. 5/6
D. 3/6
Correct Answer: C. 5/6
Calculation / Reasoning:
Find a common denominator:
2/3 = 4/6
Then:
4/6 + 1/6 = 5/6
Rationale:
4
