TEST BANK BASED ON:
Calculating Drug Dosages
A Patient-Safe Approach to Nursing and Math
3rd Edition
• Author(s)Sandra Luz Martinez de Castillo;
Maryanne Werner-McCullough
1. Chapter 1 — Section 1.1: Medication Orders & the Five
Rights
Stem: An order reads Amoxicillin 0.5 g PO. Available
tablets are 250 mg each. How many tablets should the
nurse give?
A. 1 tablet
B. 2 tablets
C. 0.5 tablet
D. 4 tablets
Correct Answer: B
Rationale — Correct: 0.5 g = 500 mg. 500 mg ÷ 250 mg/tablet =
2 tablets.
,Rationale — A: 1 tablet = 250 mg (under-dose). Mistake:
halving final division.
Rationale — C: 0.5 tablet = 125 mg (decimal place error).
Rationale — D: 4 tablets = 1000 mg (double dose) — misread g
→ mg or double conversion error.
Teaching Point: Convert units first (g → mg), then use Desired ÷
Have.
2. Chapter 1 — Section 1.2: Safe Notation & Abbreviations
Stem: Which prescription notation is considered unsafe
and should be clarified?
A. Insulin 5 units subcut
B. Insulin 5 U subcut
C. Insulin 5.0 units subcut
D. Insulin five units subcut
Correct Answer: B
Rationale — Correct: "U" (capital U) looks like a 0 or 4 and is a
known dangerous abbreviation; write "units" instead.
Rationale — A: "units" written out is safe.
Rationale — C: "5.0" (trailing zero) is also unsafe generally, but
this option spells out units and is less ambiguous than "U" —
the MOST unsafe in practice is "U".
Rationale — D: Written word "five units" is safe and
unambiguous.
,Teaching Point: Always write "units" — never use the capital
letter U.
3. Chapter 1 — Section 1.3: Pediatric Dosing & Volume
Calculations
Stem: Order: Acetaminophen 15 mg/kg PO once. Child
weight = 18 kg. Suspension available: 160 mg/5 mL. What
volume should the nurse give (round to nearest 0.1 mL)?
A. 8.4 mL
B. 8.5 mL
C. 8.0 mL
D. 9.0 mL
Correct Answer: A
Rationale — Correct: Dose = 15 mg/kg × 18 kg = 270 mg.
Volume = 270 mg × (5 mL ÷ 160 mg) = 270 × 0.03125 = 8.4375
mL → round to 8.4 mL.
Rationale — B: 8.5 mL reflects rounding up to nearest 0.5 mL
(incorrect rule for oral syringe; typical practice = nearest 0.1
mL).
Rationale — C: 8.0 mL underestimates dose (likely dropped
decimal).
Rationale — D: 9.0 mL is excessive — suggests miscalculation or
assuming 30 mg/kg.
Teaching Point: Use correct mg/kg calculation, then convert to
volume; round per device precision.
, 4. Chapter 1 — Section 1.4: IV Infusion Basics
Stem: Order: Normal saline 1,200 mL IV over 8 hours.
What is the infusion rate in mL/hr?
A. 150 mL/hr
B. 200 mL/hr
C. 100 mL/hr
D. 125 mL/hr
Correct Answer: A
Rationale — Correct: 1,200 mL ÷ 8 hr = 150 mL/hr.
Rationale — B: 200 mL/hr = 1,600 mL over 8 hr — calculation
error (1200 ÷ 6).
Rationale — C: 100 mL/hr under-infuses (1200 ÷ 12).
Rationale — D: 125 mL/hr equals 1,000 mL over 8 hr —
misdivision (1200 ÷ 9.6).
Teaching Point: mL/hr = total volume ÷ total hours.
5. Chapter 1 — Section 1.4: Gravity Drip Calculations
Stem: Infusion set delivers 10 gtt/mL. Provider orders 75
mL/hr. What is the drip rate in gtt/min (round to nearest
whole gtt/min)?
A. 12 gtt/min
B. 13 gtt/min
C. 10 gtt/min
D. 15 gtt/min
Calculating Drug Dosages
A Patient-Safe Approach to Nursing and Math
3rd Edition
• Author(s)Sandra Luz Martinez de Castillo;
Maryanne Werner-McCullough
1. Chapter 1 — Section 1.1: Medication Orders & the Five
Rights
Stem: An order reads Amoxicillin 0.5 g PO. Available
tablets are 250 mg each. How many tablets should the
nurse give?
A. 1 tablet
B. 2 tablets
C. 0.5 tablet
D. 4 tablets
Correct Answer: B
Rationale — Correct: 0.5 g = 500 mg. 500 mg ÷ 250 mg/tablet =
2 tablets.
,Rationale — A: 1 tablet = 250 mg (under-dose). Mistake:
halving final division.
Rationale — C: 0.5 tablet = 125 mg (decimal place error).
Rationale — D: 4 tablets = 1000 mg (double dose) — misread g
→ mg or double conversion error.
Teaching Point: Convert units first (g → mg), then use Desired ÷
Have.
2. Chapter 1 — Section 1.2: Safe Notation & Abbreviations
Stem: Which prescription notation is considered unsafe
and should be clarified?
A. Insulin 5 units subcut
B. Insulin 5 U subcut
C. Insulin 5.0 units subcut
D. Insulin five units subcut
Correct Answer: B
Rationale — Correct: "U" (capital U) looks like a 0 or 4 and is a
known dangerous abbreviation; write "units" instead.
Rationale — A: "units" written out is safe.
Rationale — C: "5.0" (trailing zero) is also unsafe generally, but
this option spells out units and is less ambiguous than "U" —
the MOST unsafe in practice is "U".
Rationale — D: Written word "five units" is safe and
unambiguous.
,Teaching Point: Always write "units" — never use the capital
letter U.
3. Chapter 1 — Section 1.3: Pediatric Dosing & Volume
Calculations
Stem: Order: Acetaminophen 15 mg/kg PO once. Child
weight = 18 kg. Suspension available: 160 mg/5 mL. What
volume should the nurse give (round to nearest 0.1 mL)?
A. 8.4 mL
B. 8.5 mL
C. 8.0 mL
D. 9.0 mL
Correct Answer: A
Rationale — Correct: Dose = 15 mg/kg × 18 kg = 270 mg.
Volume = 270 mg × (5 mL ÷ 160 mg) = 270 × 0.03125 = 8.4375
mL → round to 8.4 mL.
Rationale — B: 8.5 mL reflects rounding up to nearest 0.5 mL
(incorrect rule for oral syringe; typical practice = nearest 0.1
mL).
Rationale — C: 8.0 mL underestimates dose (likely dropped
decimal).
Rationale — D: 9.0 mL is excessive — suggests miscalculation or
assuming 30 mg/kg.
Teaching Point: Use correct mg/kg calculation, then convert to
volume; round per device precision.
, 4. Chapter 1 — Section 1.4: IV Infusion Basics
Stem: Order: Normal saline 1,200 mL IV over 8 hours.
What is the infusion rate in mL/hr?
A. 150 mL/hr
B. 200 mL/hr
C. 100 mL/hr
D. 125 mL/hr
Correct Answer: A
Rationale — Correct: 1,200 mL ÷ 8 hr = 150 mL/hr.
Rationale — B: 200 mL/hr = 1,600 mL over 8 hr — calculation
error (1200 ÷ 6).
Rationale — C: 100 mL/hr under-infuses (1200 ÷ 12).
Rationale — D: 125 mL/hr equals 1,000 mL over 8 hr —
misdivision (1200 ÷ 9.6).
Teaching Point: mL/hr = total volume ÷ total hours.
5. Chapter 1 — Section 1.4: Gravity Drip Calculations
Stem: Infusion set delivers 10 gtt/mL. Provider orders 75
mL/hr. What is the drip rate in gtt/min (round to nearest
whole gtt/min)?
A. 12 gtt/min
B. 13 gtt/min
C. 10 gtt/min
D. 15 gtt/min
