DOSAGE CALCULATIONS MADE
EASY
SOLVING PROBLEMS USING
DIMENSIONAL ANALYSIS
8TH EDITION
• AUTHOR(S)GLORIA PEARL
CRAIG
TEST BANK
,Question 1
The healthcare provider orders amoxicillin 500 mg PO every 12
hours for a patient with a respiratory infection. The available
medication is amoxicillin oral suspension 250 mg/5 mL. How
many mL should the nurse administer per dose?
A. 2 mL
B. 5 mL
C. 10 mL
D. 20 mL
Correct Answer: C
Rationale:
This problem requires a simple conversion using the available
concentration to find the desired volume.
Step 1: Identify the known quantities.
Ordered: 500 mg
Available: 250 mg / 5 mL
Step 2: Set up the dimensional analysis equation.
The goal is to cancel out the unit we don't want (mg) and end
with the unit we do want (mL).
mL per dose = (500 mg / 1) × (5 mL / 250 mg)
,Step 3: Perform the calculation.
mL per dose = (500 × 5) / 250 mL = = 10 mL
Medication Safety Note:
Always double-check that the dose ordered is within the safe
range for the patient and confirm the route of administration.
For liquid medications, use an appropriate measuring device
(e.g., oral syringe or medicine cup) and ensure the patient can
swallow safely.
Question 2
A nurse needs to convert a patient's weight from 176 pounds
to kilograms. What is the patient's weight in kilograms?
(Round to the nearest tenth).
A. 60.0 kg
B. 70.0 kg
C. 80.0 kg
D. 90.0 kg
Correct Answer: C
Rationale:
This is a fundamental unit conversion from the household
system to the metric system. The conversion factor is 2.2 lb = 1
kg.
, Step 1: Identify the known quantities.
Weight: 176 lb
Conversion: 1 kg / 2.2 lb
Step 2: Set up the dimensional analysis equation.
kg = (176 lb / 1) × (1 kg / 2.2 lb)
Step 3: Perform the calculation.
kg = .2 = 80 kg
Medication Safety Note:
Accurate weight conversion is the cornerstone of safe
medication administration, especially for calculating weight-
based doses and renal function. Always round weights to the
nearest tenth as per facility policy.
Question 3
A patient is prescribed metoprolol 25 mg PO daily. The
pharmacy provides tablets labeled 50 mg. How many tablets
should the nurse administer?
A. 0.25 tablets
B. 0.5 tablets
C. 1 tablet
D. 2 tablets
Correct Answer: B
EASY
SOLVING PROBLEMS USING
DIMENSIONAL ANALYSIS
8TH EDITION
• AUTHOR(S)GLORIA PEARL
CRAIG
TEST BANK
,Question 1
The healthcare provider orders amoxicillin 500 mg PO every 12
hours for a patient with a respiratory infection. The available
medication is amoxicillin oral suspension 250 mg/5 mL. How
many mL should the nurse administer per dose?
A. 2 mL
B. 5 mL
C. 10 mL
D. 20 mL
Correct Answer: C
Rationale:
This problem requires a simple conversion using the available
concentration to find the desired volume.
Step 1: Identify the known quantities.
Ordered: 500 mg
Available: 250 mg / 5 mL
Step 2: Set up the dimensional analysis equation.
The goal is to cancel out the unit we don't want (mg) and end
with the unit we do want (mL).
mL per dose = (500 mg / 1) × (5 mL / 250 mg)
,Step 3: Perform the calculation.
mL per dose = (500 × 5) / 250 mL = = 10 mL
Medication Safety Note:
Always double-check that the dose ordered is within the safe
range for the patient and confirm the route of administration.
For liquid medications, use an appropriate measuring device
(e.g., oral syringe or medicine cup) and ensure the patient can
swallow safely.
Question 2
A nurse needs to convert a patient's weight from 176 pounds
to kilograms. What is the patient's weight in kilograms?
(Round to the nearest tenth).
A. 60.0 kg
B. 70.0 kg
C. 80.0 kg
D. 90.0 kg
Correct Answer: C
Rationale:
This is a fundamental unit conversion from the household
system to the metric system. The conversion factor is 2.2 lb = 1
kg.
, Step 1: Identify the known quantities.
Weight: 176 lb
Conversion: 1 kg / 2.2 lb
Step 2: Set up the dimensional analysis equation.
kg = (176 lb / 1) × (1 kg / 2.2 lb)
Step 3: Perform the calculation.
kg = .2 = 80 kg
Medication Safety Note:
Accurate weight conversion is the cornerstone of safe
medication administration, especially for calculating weight-
based doses and renal function. Always round weights to the
nearest tenth as per facility policy.
Question 3
A patient is prescribed metoprolol 25 mg PO daily. The
pharmacy provides tablets labeled 50 mg. How many tablets
should the nurse administer?
A. 0.25 tablets
B. 0.5 tablets
C. 1 tablet
D. 2 tablets
Correct Answer: B
