DOSAGE CALCULATIONS MADE
EASY
SOLVING PROBLEMS USING
DIMENSIONAL ANALYSIS
8TH EDITION
• AUTHOR(S)GLORIA PEARL
CRAIG
TEST BANK
,Question 1
Topic: Dimensional Analysis Fundamentals
Difficulty: Easy
The healthcare provider orders cephalexin 500 mg by mouth
every 6 hours for a patient with a skin infection. The medication
is available in 250 mg/5 mL suspension. How many mL will the
nurse administer per dose?
A. 5 mL
B. 10 mL
C. 15 mL
D. 20 mL
Correct Answer: B
Rationale:
Step 1: Identify the desired dose (500 mg) and the available
concentration (250 mg/5 mL).
Step 2: Set up the dimensional analysis equation to cancel units
and solve for mL.
5 mL250 mg×500 mg= mL per dose250 mg5 mL
×500 mg= mL per dose
Step 3: Cancel the units (mg), multiply the numerators, and
divide by the denominator.
5 mL×500250=2500250=10 mL2505 mL×500=2502500=10 mL
,Medication Safety Note: Always double-check that the final
volume is a reasonable amount to administer. For a high-
volume liquid medication, consider dividing the dose if
appropriate or using a different concentration. Re-calculate if
the volume seems unusually high or low.
Question 2
Topic: Oral Dosage Calculations (Tablets)
Difficulty: Easy
A patient is prescribed metoprolol tartrate 25 mg orally twice
daily for hypertension. The pharmacy provides 50 mg tablets.
How many tablets will the nurse administer for one dose?
A. 0.25 tablet
B. 0.5 tablet
C. 1 tablet
D. 2 tablets
Correct Answer: B
Rationale:
Step 1: Identify the desired dose (25 mg) and the available dose
(50 mg/tablet).
Step 2: Set up the dimensional analysis equation.
1 tablet50 mg×25 mg= tablets per dose50 mg1 tablet
×25 mg= tablets per dose
, Step 3: Cancel the units (mg) and solve.
1×2550=2550=0.5 tablet501×25=5025=0.5 tablet
Medication Safety Note: Scored tablets can be safely split. If a
tablet is not scored, it should not be broken, and an alternative
dosage form should be requested. Always use a tablet splitter
for accuracy and safety.
Question 3
Topic: Injectable Medication Calculations (IV Push)
Difficulty: Easy
The healthcare provider orders ondansetron 4 mg IV push for a
patient experiencing postoperative nausea. The vial is labeled 2
mg/mL. How many mL will the nurse draw up for the correct
dose?
A. 1 mL
B. 2 mL
C. 4 mL
D. 8 mL
Correct Answer: B
Rationale:
Step 1: Identify the desired dose (4 mg) and the available
concentration (2 mg/mL).
Step 2: Set up the dimensional analysis equation.
EASY
SOLVING PROBLEMS USING
DIMENSIONAL ANALYSIS
8TH EDITION
• AUTHOR(S)GLORIA PEARL
CRAIG
TEST BANK
,Question 1
Topic: Dimensional Analysis Fundamentals
Difficulty: Easy
The healthcare provider orders cephalexin 500 mg by mouth
every 6 hours for a patient with a skin infection. The medication
is available in 250 mg/5 mL suspension. How many mL will the
nurse administer per dose?
A. 5 mL
B. 10 mL
C. 15 mL
D. 20 mL
Correct Answer: B
Rationale:
Step 1: Identify the desired dose (500 mg) and the available
concentration (250 mg/5 mL).
Step 2: Set up the dimensional analysis equation to cancel units
and solve for mL.
5 mL250 mg×500 mg= mL per dose250 mg5 mL
×500 mg= mL per dose
Step 3: Cancel the units (mg), multiply the numerators, and
divide by the denominator.
5 mL×500250=2500250=10 mL2505 mL×500=2502500=10 mL
,Medication Safety Note: Always double-check that the final
volume is a reasonable amount to administer. For a high-
volume liquid medication, consider dividing the dose if
appropriate or using a different concentration. Re-calculate if
the volume seems unusually high or low.
Question 2
Topic: Oral Dosage Calculations (Tablets)
Difficulty: Easy
A patient is prescribed metoprolol tartrate 25 mg orally twice
daily for hypertension. The pharmacy provides 50 mg tablets.
How many tablets will the nurse administer for one dose?
A. 0.25 tablet
B. 0.5 tablet
C. 1 tablet
D. 2 tablets
Correct Answer: B
Rationale:
Step 1: Identify the desired dose (25 mg) and the available dose
(50 mg/tablet).
Step 2: Set up the dimensional analysis equation.
1 tablet50 mg×25 mg= tablets per dose50 mg1 tablet
×25 mg= tablets per dose
, Step 3: Cancel the units (mg) and solve.
1×2550=2550=0.5 tablet501×25=5025=0.5 tablet
Medication Safety Note: Scored tablets can be safely split. If a
tablet is not scored, it should not be broken, and an alternative
dosage form should be requested. Always use a tablet splitter
for accuracy and safety.
Question 3
Topic: Injectable Medication Calculations (IV Push)
Difficulty: Easy
The healthcare provider orders ondansetron 4 mg IV push for a
patient experiencing postoperative nausea. The vial is labeled 2
mg/mL. How many mL will the nurse draw up for the correct
dose?
A. 1 mL
B. 2 mL
C. 4 mL
D. 8 mL
Correct Answer: B
Rationale:
Step 1: Identify the desired dose (4 mg) and the available
concentration (2 mg/mL).
Step 2: Set up the dimensional analysis equation.
