DOSAGE CALCULATIONS MADE
EASY
SOLVING PROBLEMS USING
DIMENSIONAL ANALYSIS
8TH EDITION
• AUTHOR(S)GLORIA PEARL
CRAIG
TEST BANK
,Question 1 (Easy) — Oral Tablet Dosage Calculation
A nurse receives the following medication order:
Amoxicillin 750 mg PO every 12 hours
Available medication: Amoxicillin 250 mg tablets
How many tablets should the nurse administer for each dose?
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: Set up dimensional analysis.
750 mg×1 tablet250 mg750\ \text{mg}\times\frac{1\
\text{tablet}}{250\ \text{mg}}750 mg×250 mg1 tablet
The milligrams cancel.
=750250 tablets=3 tablets=\frac{750}{250}\text{
tablets}=3\text{ tablets}=250750 tablets=3 tablets
,Step 3: Verify the result.
3 tablets × 250 mg/tablet = 750 mg ✓
Medication Safety Note:
Always compare the prescribed dose with the available strength
before administering tablets. Verify that the calculated number
of tablets is reasonable and consistent with the medication
order.
Question 2 (Easy) — Liquid Medication Calculation
A child is prescribed:
Acetaminophen 480 mg PO
The medication available is:
160 mg per 5 mL
How many milliliters should the nurse administer?
A. 10 mL
B. 12.5 mL
C. 15 mL
D. 20 mL
Correct Answer: C. 15 mL
Rationale
, Step 1: Identify the ordered dose and concentration.
• Ordered = 480 mg
• Available = 160 mg/5 mL
Step 2: Dimensional analysis.
480 mg×5 mL160 mg480\ \text{mg}\times\frac{5\
\text{mL}}{160\ \text{mg}}480 mg×160 mg5 mL
Milligrams cancel.
=480×5160=15 mL=\frac{480\times5}{160}=15\
\text{mL}=160480×5=15 mL
Step 3: Verify the calculation.
15 mL contains:
160 mg5 mL×15 mL=480 mg\frac{160\ \text{mg}}{5\
\text{mL}}\times15\ \text{mL}=480\ \text{mg}5 mL160 mg
×15 mL=480 mg
✓ Correct.
Medication Safety Note:
Measure liquid medications using an oral dosing syringe or
calibrated medication cup rather than household spoons to
improve dosing accuracy.
Question 3 (Easy) — Injectable Medication
EASY
SOLVING PROBLEMS USING
DIMENSIONAL ANALYSIS
8TH EDITION
• AUTHOR(S)GLORIA PEARL
CRAIG
TEST BANK
,Question 1 (Easy) — Oral Tablet Dosage Calculation
A nurse receives the following medication order:
Amoxicillin 750 mg PO every 12 hours
Available medication: Amoxicillin 250 mg tablets
How many tablets should the nurse administer for each dose?
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: Set up dimensional analysis.
750 mg×1 tablet250 mg750\ \text{mg}\times\frac{1\
\text{tablet}}{250\ \text{mg}}750 mg×250 mg1 tablet
The milligrams cancel.
=750250 tablets=3 tablets=\frac{750}{250}\text{
tablets}=3\text{ tablets}=250750 tablets=3 tablets
,Step 3: Verify the result.
3 tablets × 250 mg/tablet = 750 mg ✓
Medication Safety Note:
Always compare the prescribed dose with the available strength
before administering tablets. Verify that the calculated number
of tablets is reasonable and consistent with the medication
order.
Question 2 (Easy) — Liquid Medication Calculation
A child is prescribed:
Acetaminophen 480 mg PO
The medication available is:
160 mg per 5 mL
How many milliliters should the nurse administer?
A. 10 mL
B. 12.5 mL
C. 15 mL
D. 20 mL
Correct Answer: C. 15 mL
Rationale
, Step 1: Identify the ordered dose and concentration.
• Ordered = 480 mg
• Available = 160 mg/5 mL
Step 2: Dimensional analysis.
480 mg×5 mL160 mg480\ \text{mg}\times\frac{5\
\text{mL}}{160\ \text{mg}}480 mg×160 mg5 mL
Milligrams cancel.
=480×5160=15 mL=\frac{480\times5}{160}=15\
\text{mL}=160480×5=15 mL
Step 3: Verify the calculation.
15 mL contains:
160 mg5 mL×15 mL=480 mg\frac{160\ \text{mg}}{5\
\text{mL}}\times15\ \text{mL}=480\ \text{mg}5 mL160 mg
×15 mL=480 mg
✓ Correct.
Medication Safety Note:
Measure liquid medications using an oral dosing syringe or
calibrated medication cup rather than household spoons to
improve dosing accuracy.
Question 3 (Easy) — Injectable Medication
