Solving Problems Using Dimensional

DOSAGE CALCULATIONS MADE
EASY
SOLVING PROBLEMS USING
DIMENSIONAL ANALYSIS
8TH EDITION
• AUTHOR(S)GLORIA PEARL
CRAIG




TEST BANK

,Question 1 (Easy – Oral Tablet Calculation)
A patient is prescribed amoxicillin 750 mg PO. The medication
available is 250 mg per tablet. How many tablets should the
nurse administer?
A. 2 tablets
B. 2.5 tablets
C. 3 tablets
D. 4 tablets
Correct Answer: C. 3 tablets
Rationale:
Step 1: Identify the ordered dose and available strength.
Ordered = 750 mg
Available = 250 mg/tablet
Step 2: Dimensional analysis
[
750\ \text{mg}\times\frac{1\ \text{tablet}}{250\ \text{mg}}=3\
\text{tablets}
]
Step 3: Administer 3 tablets.
Medication Safety Note:
Always verify whether tablets are scored before splitting doses.

,Question 2 (Easy – Liquid Medication)
A provider prescribes cephalexin 500 mg PO. The suspension
available contains 250 mg per 5 mL. How many milliliters should
the nurse administer?
A. 5 mL
B. 7.5 mL
C. 10 mL
D. 15 mL
Correct Answer: C. 10 mL
Rationale:
Step 1:
Ordered = 500 mg
Available = 250 mg/5 mL
Step 2:
[
500\ \text{mg}\times\frac{5\ \text{mL}}{250\ \text{mg}}=10\
\text{mL}
]
Step 3:

, Administer 10 mL.
Medication Safety Note:
Measure liquid medications with an oral syringe or medication
cup rather than a household spoon.


Question 3 (Easy – Unit Conversion)
The provider orders 1.5 g of an antibiotic IV. How many
milligrams is this?
A. 150 mg
B. 1,500 mg
C. 15,000 mg
D. 150,000 mg
Correct Answer: B. 1,500 mg
Rationale:
Step 1:
1 g = 1,000 mg
Step 2:
[
1.5\ \text{g}\times\frac{1000\ \text{mg}}{1\ \text{g}}=1500\
\text{mg}
]