CALCULATION OF DRUG DOSAGES: A WORK TEXT
12TH EDITION
AUTHOR(S)SHEILA J. OGDEN; LINDA FLUHARTY
QUESTION 1
Category: [Basic Mathematics]
Difficulty: Foundational
Question:
A nursing student is reviewing fractions before beginning medication-calculation
problems. Which fraction is equivalent to 1/2?
A. 2/3
B. 3/6
C. 4/10
D. 5/12
Correct Answer: B. 3/6
Calculation / Reasoning:
Multiply both the numerator and denominator of 1/2 by 3:
1×32×3=36\frac{1\times3}{2\times3}=\frac{3}{6}
Therefore, 3/6 is equivalent to 1/2.
Rationale:
Equivalent fractions represent the same quantity even though their numerators and
denominators differ. Multiplying the numerator and denominator by the same nonzero
number preserves the fraction's value. This skill is important because medication
calculations may require fractions to be converted into equivalent forms before
addition, subtraction, or comparison.
Why the other options are incorrect:
1
,A. 2/3 is not equivalent to 1/2.
B. 3/6 equals 1/2 and is correct.
C. 4/10 simplifies to 2/5.
D. 5/12 does not equal 1/2.
Clinical Focus: Equivalent fractions allow nurses to recognize when different
numerical representations describe the same quantity.
QUESTION 2
Category: [Basic Mathematics]
Difficulty: Foundational
Question:
Which fraction is already in lowest terms?
A. 6/8
B. 9/12
C. 5/7
D. 12/18
Correct Answer: C. 5/7
Calculation / Reasoning:
A fraction is in lowest terms when the numerator and denominator have no common
factor other than 1.
• 6/8 → divide by 2 = 3/4
• 9/12 → divide by 3 = 3/4
• 5/7 → no common factor other than 1
• 12/18 → divide by 6 = 2/3
Therefore, 5/7 is already simplified.
Rationale:
Simplifying fractions is a foundational mathematical skill. The numerator and
denominator should be divided by their greatest common factor when reducing a
fraction. Recognizing fractions in lowest terms helps prevent unnecessary
mathematical steps during dosage calculations.
2
,Why the other options are incorrect:
A. 6/8 can be reduced to 3/4.
B. 9/12 can be reduced to 3/4.
C. 5/7 is already in lowest terms.
D. 12/18 can be reduced to 2/3.
Clinical Focus: Simplify fractions accurately before using them in subsequent
calculations.
QUESTION 3
Category: [Conversions]
Difficulty: Foundational
Question:
A student needs to convert the mixed number 2 1/4 into an improper fraction. Which
answer is correct?
A. 7/4
B. 8/4
C. 9/4
D. 10/4
Correct Answer: C. 9/4
Calculation / Reasoning:
Multiply the whole number by the denominator:
2×4=82\times4=8
Add the numerator:
8+1=98+1=9
Keep the denominator:
94\frac{9}{4}
Rationale:
To convert a mixed number to an improper fraction, multiply the whole number by the
denominator, add the numerator, and place the result over the original denominator.
Why the other options are incorrect:
3
, A. 7/4 would result from an incorrect conversion.
B. 8/4 omits the numerator.
C. 9/4 is correct.
D. 10/4 results from adding an incorrect amount to the product.
Clinical Focus: Correct conversion between mixed and improper fractions prevents
downstream calculation errors.
QUESTION 4
Category: [Conversions]
Difficulty: Foundational
Question:
Which mixed number is equivalent to the improper fraction 11/4?
A. 2 1/4
B. 2 3/4
C. 3 1/4
D. 3 3/4
Correct Answer: B. 2 3/4
Calculation / Reasoning:
Divide 11 by 4:
11÷4=2 remainder 311\div4=2\text{ remainder }3
Therefore:
114=234\frac{11}{4}=2\frac{3}{4}
Rationale:
An improper fraction is converted to a mixed number by dividing the numerator by the
denominator. The quotient becomes the whole number, and the remainder becomes
the numerator of the fractional portion.
Why the other options are incorrect:
A. 2 1/4 equals 9/4.
B. 2 3/4 equals 11/4 and is correct.
C. 3 1/4 equals 13/4.
D. 3 3/4 equals 15/4.
4
12TH EDITION
AUTHOR(S)SHEILA J. OGDEN; LINDA FLUHARTY
QUESTION 1
Category: [Basic Mathematics]
Difficulty: Foundational
Question:
A nursing student is reviewing fractions before beginning medication-calculation
problems. Which fraction is equivalent to 1/2?
A. 2/3
B. 3/6
C. 4/10
D. 5/12
Correct Answer: B. 3/6
Calculation / Reasoning:
Multiply both the numerator and denominator of 1/2 by 3:
1×32×3=36\frac{1\times3}{2\times3}=\frac{3}{6}
Therefore, 3/6 is equivalent to 1/2.
Rationale:
Equivalent fractions represent the same quantity even though their numerators and
denominators differ. Multiplying the numerator and denominator by the same nonzero
number preserves the fraction's value. This skill is important because medication
calculations may require fractions to be converted into equivalent forms before
addition, subtraction, or comparison.
Why the other options are incorrect:
1
,A. 2/3 is not equivalent to 1/2.
B. 3/6 equals 1/2 and is correct.
C. 4/10 simplifies to 2/5.
D. 5/12 does not equal 1/2.
Clinical Focus: Equivalent fractions allow nurses to recognize when different
numerical representations describe the same quantity.
QUESTION 2
Category: [Basic Mathematics]
Difficulty: Foundational
Question:
Which fraction is already in lowest terms?
A. 6/8
B. 9/12
C. 5/7
D. 12/18
Correct Answer: C. 5/7
Calculation / Reasoning:
A fraction is in lowest terms when the numerator and denominator have no common
factor other than 1.
• 6/8 → divide by 2 = 3/4
• 9/12 → divide by 3 = 3/4
• 5/7 → no common factor other than 1
• 12/18 → divide by 6 = 2/3
Therefore, 5/7 is already simplified.
Rationale:
Simplifying fractions is a foundational mathematical skill. The numerator and
denominator should be divided by their greatest common factor when reducing a
fraction. Recognizing fractions in lowest terms helps prevent unnecessary
mathematical steps during dosage calculations.
2
,Why the other options are incorrect:
A. 6/8 can be reduced to 3/4.
B. 9/12 can be reduced to 3/4.
C. 5/7 is already in lowest terms.
D. 12/18 can be reduced to 2/3.
Clinical Focus: Simplify fractions accurately before using them in subsequent
calculations.
QUESTION 3
Category: [Conversions]
Difficulty: Foundational
Question:
A student needs to convert the mixed number 2 1/4 into an improper fraction. Which
answer is correct?
A. 7/4
B. 8/4
C. 9/4
D. 10/4
Correct Answer: C. 9/4
Calculation / Reasoning:
Multiply the whole number by the denominator:
2×4=82\times4=8
Add the numerator:
8+1=98+1=9
Keep the denominator:
94\frac{9}{4}
Rationale:
To convert a mixed number to an improper fraction, multiply the whole number by the
denominator, add the numerator, and place the result over the original denominator.
Why the other options are incorrect:
3
, A. 7/4 would result from an incorrect conversion.
B. 8/4 omits the numerator.
C. 9/4 is correct.
D. 10/4 results from adding an incorrect amount to the product.
Clinical Focus: Correct conversion between mixed and improper fractions prevents
downstream calculation errors.
QUESTION 4
Category: [Conversions]
Difficulty: Foundational
Question:
Which mixed number is equivalent to the improper fraction 11/4?
A. 2 1/4
B. 2 3/4
C. 3 1/4
D. 3 3/4
Correct Answer: B. 2 3/4
Calculation / Reasoning:
Divide 11 by 4:
11÷4=2 remainder 311\div4=2\text{ remainder }3
Therefore:
114=234\frac{11}{4}=2\frac{3}{4}
Rationale:
An improper fraction is converted to a mixed number by dividing the numerator by the
denominator. The quotient becomes the whole number, and the remainder becomes
the numerator of the fractional portion.
Why the other options are incorrect:
A. 2 1/4 equals 9/4.
B. 2 3/4 equals 11/4 and is correct.
C. 3 1/4 equals 13/4.
D. 3 3/4 equals 15/4.
4
