DOSAGE CALCULATIONS MADE
EASY
SOLVING PROBLEMS USING
DIMENSIONAL ANALYSIS
8TH EDITION
• AUTHOR(S)GLORIA PEARL
CRAIG
TEST BANK
,Question 1 (Easy) — Dimensional Analysis Fundamentals
A provider prescribes amoxicillin 750 mg orally. The medication
available is 250 mg per capsule.
How many capsules should the nurse administer?
A. 2 capsules
B. 2.5 capsules
C. 3 capsules
D. 4 capsules
Correct Answer: C. 3 capsules
Rationale
Step 1: Identify the ordered dose
Ordered = 750 mg
Step 2: Identify the available dose
Available = 250 mg/capsule
Step 3: Set up dimensional analysis
750 mg×1 capsule250 mg=3 capsules750\
\text{mg}\times\frac{1\ \text{capsule}}{250\ \text{mg}} =3\
\text{capsules}750 mg×250 mg1 capsule=3 capsules
The milligrams cancel, leaving capsules.
Step 4: Verify
3 capsules × 250 mg = 750 mg ✓
,Medication Safety Note:
Always verify that the calculated number of tablets or capsules
is reasonable. If an unusually large number is required, recheck
the prescription and calculation before administration.
Question 2 (Easy) — Oral Liquid Dosage Calculation
A patient is prescribed 600 mg of acetaminophen orally.
The medication label reads:
Acetaminophen oral solution 300 mg/10 mL
How many milliliters should the nurse administer?
A. 10 mL
B. 15 mL
C. 20 mL
D. 30 mL
Correct Answer: C. 20 mL
Rationale
Step 1: Ordered dose
600 mg
Step 2: Available concentration
300 mg per 10 mL
, Step 3: Dimensional analysis
600 mg×10 mL300 mg=20 mL600\ \text{mg}\times\frac{10\
\text{mL}}{300\ \text{mg}} =20\ \text{mL}600 mg×300 mg10 mL
=20 mL
Milligrams cancel, leaving milliliters.
Step 4: Verify
20 mL contains:
20×30010=600 mg20\times\frac{300}{10}=600\
\text{mg}20×10300=600 mg
Correct.
Medication Safety Note:
Use an oral medication syringe or medication cup with accurate
graduations when measuring liquid medications.
Question 3 (Easy) — Injectable Medication
The provider orders cefazolin 500 mg IM.
The vial available contains:
Cefazolin 1 g/4 mL after reconstitution.
How many milliliters should the nurse administer?
A. 1 mL
EASY
SOLVING PROBLEMS USING
DIMENSIONAL ANALYSIS
8TH EDITION
• AUTHOR(S)GLORIA PEARL
CRAIG
TEST BANK
,Question 1 (Easy) — Dimensional Analysis Fundamentals
A provider prescribes amoxicillin 750 mg orally. The medication
available is 250 mg per capsule.
How many capsules should the nurse administer?
A. 2 capsules
B. 2.5 capsules
C. 3 capsules
D. 4 capsules
Correct Answer: C. 3 capsules
Rationale
Step 1: Identify the ordered dose
Ordered = 750 mg
Step 2: Identify the available dose
Available = 250 mg/capsule
Step 3: Set up dimensional analysis
750 mg×1 capsule250 mg=3 capsules750\
\text{mg}\times\frac{1\ \text{capsule}}{250\ \text{mg}} =3\
\text{capsules}750 mg×250 mg1 capsule=3 capsules
The milligrams cancel, leaving capsules.
Step 4: Verify
3 capsules × 250 mg = 750 mg ✓
,Medication Safety Note:
Always verify that the calculated number of tablets or capsules
is reasonable. If an unusually large number is required, recheck
the prescription and calculation before administration.
Question 2 (Easy) — Oral Liquid Dosage Calculation
A patient is prescribed 600 mg of acetaminophen orally.
The medication label reads:
Acetaminophen oral solution 300 mg/10 mL
How many milliliters should the nurse administer?
A. 10 mL
B. 15 mL
C. 20 mL
D. 30 mL
Correct Answer: C. 20 mL
Rationale
Step 1: Ordered dose
600 mg
Step 2: Available concentration
300 mg per 10 mL
, Step 3: Dimensional analysis
600 mg×10 mL300 mg=20 mL600\ \text{mg}\times\frac{10\
\text{mL}}{300\ \text{mg}} =20\ \text{mL}600 mg×300 mg10 mL
=20 mL
Milligrams cancel, leaving milliliters.
Step 4: Verify
20 mL contains:
20×30010=600 mg20\times\frac{300}{10}=600\
\text{mg}20×10300=600 mg
Correct.
Medication Safety Note:
Use an oral medication syringe or medication cup with accurate
graduations when measuring liquid medications.
Question 3 (Easy) — Injectable Medication
The provider orders cefazolin 500 mg IM.
The vial available contains:
Cefazolin 1 g/4 mL after reconstitution.
How many milliliters should the nurse administer?
A. 1 mL
