DOSAGE CALCULATIONS MADE
EASY
SOLVING PROBLEMS USING
DIMENSIONAL ANALYSIS
8TH EDITION
• AUTHOR(S)GLORIA PEARL
CRAIG
TEST BANK
,Question 1
Topic: Dimensional Analysis Fundamentals
The healthcare provider orders amoxicillin 0.5 g PO twice daily.
The medication available is amoxicillin 250 mg tablets. How
many tablets should the nurse administer per dose?
A. 0.5 tablet
B. 1 tablet
C. 2 tablets
D. 4 tablets
Correct Answer: C. 2 tablets
Rationale:
Step 1: Identify the ordered dose and available medication.
• Ordered: 0.5 g
• Available: 250 mg per tablet
Step 2: Set up dimensional analysis to convert grams to
milligrams and calculate tablets.
0.5 g1×1000 mg1 g×1 tablet250 mg=0.5×1000250 tablets10.5 g
×1 g1000 mg×250 mg1 tablet=2500.5×1000 tablets
Step 3: Complete the calculation.
500250=2 tablets250500=2 tablets
,Medication Safety Note: Always ensure unit conversion is
complete before calculating the number of tablets. Double-
check that the order is for the correct time frame (per dose
versus per day) and verify the medication with a second nurse
when administering.
Question 2
Topic: Oral Dosage Calculations
A patient is prescribed digoxin 0.125 mg PO daily. The pharmacy
provides digoxin 0.25 mg tablets. How many tablets will the
nurse administer?
A. 0.25 tablet
B. 0.5 tablet
C. 1 tablet
D. 2 tablets
Correct Answer: B. 0.5 tablet
Rationale:
Step 1: Identify the ordered dose and available medication.
• Ordered: 0.125 mg
• Available: 0.25 mg per tablet
Step 2: Set up dimensional analysis.
, 0.125 mg1×1 tablet0.25 mg=0.1250.25 tablets10.125 mg
×0.25 mg1 tablet=0.250.125 tablets
Step 3: Complete the calculation.
0.125÷0.25=0.5 tablet0.125÷0.25=0.5 tablet
Medication Safety Note: Scored tablets may be split when half
tablets are required. Always check with the pharmacy if the
tablet is scored and appropriate for splitting. Digoxin has a
narrow therapeutic range, making accurate dosing critical for
patient safety.
Question 3
Topic: Liquid Medication Calculations
The healthcare provider orders cephalexin 750 mg PO every 6
hours. The available liquid medication is cephalexin 250 mg/5
mL. How many milliliters will the nurse administer per dose?
A. 5 mL
B. 10 mL
C. 15 mL
D. 20 mL
Correct Answer: C. 15 mL
Rationale:
Step 1: Identify the ordered dose and available concentration.
EASY
SOLVING PROBLEMS USING
DIMENSIONAL ANALYSIS
8TH EDITION
• AUTHOR(S)GLORIA PEARL
CRAIG
TEST BANK
,Question 1
Topic: Dimensional Analysis Fundamentals
The healthcare provider orders amoxicillin 0.5 g PO twice daily.
The medication available is amoxicillin 250 mg tablets. How
many tablets should the nurse administer per dose?
A. 0.5 tablet
B. 1 tablet
C. 2 tablets
D. 4 tablets
Correct Answer: C. 2 tablets
Rationale:
Step 1: Identify the ordered dose and available medication.
• Ordered: 0.5 g
• Available: 250 mg per tablet
Step 2: Set up dimensional analysis to convert grams to
milligrams and calculate tablets.
0.5 g1×1000 mg1 g×1 tablet250 mg=0.5×1000250 tablets10.5 g
×1 g1000 mg×250 mg1 tablet=2500.5×1000 tablets
Step 3: Complete the calculation.
500250=2 tablets250500=2 tablets
,Medication Safety Note: Always ensure unit conversion is
complete before calculating the number of tablets. Double-
check that the order is for the correct time frame (per dose
versus per day) and verify the medication with a second nurse
when administering.
Question 2
Topic: Oral Dosage Calculations
A patient is prescribed digoxin 0.125 mg PO daily. The pharmacy
provides digoxin 0.25 mg tablets. How many tablets will the
nurse administer?
A. 0.25 tablet
B. 0.5 tablet
C. 1 tablet
D. 2 tablets
Correct Answer: B. 0.5 tablet
Rationale:
Step 1: Identify the ordered dose and available medication.
• Ordered: 0.125 mg
• Available: 0.25 mg per tablet
Step 2: Set up dimensional analysis.
, 0.125 mg1×1 tablet0.25 mg=0.1250.25 tablets10.125 mg
×0.25 mg1 tablet=0.250.125 tablets
Step 3: Complete the calculation.
0.125÷0.25=0.5 tablet0.125÷0.25=0.5 tablet
Medication Safety Note: Scored tablets may be split when half
tablets are required. Always check with the pharmacy if the
tablet is scored and appropriate for splitting. Digoxin has a
narrow therapeutic range, making accurate dosing critical for
patient safety.
Question 3
Topic: Liquid Medication Calculations
The healthcare provider orders cephalexin 750 mg PO every 6
hours. The available liquid medication is cephalexin 250 mg/5
mL. How many milliliters will the nurse administer per dose?
A. 5 mL
B. 10 mL
C. 15 mL
D. 20 mL
Correct Answer: C. 15 mL
Rationale:
Step 1: Identify the ordered dose and available concentration.
