Henke’s Med-Math Test Bank Nursing Test Bank 2026 | Dosage Calculation Nursing MCQs & Medication Administration Math Guide

HENKE'S MED-MATH
DOSAGE CALCULATION, PREPARATION
& ADMINISTRATION
10TH EDITION
• AUTHOR(S)SUSAN BUCHHOLZ


TEST BANK
1. Reference: Ch. 1 — Multiplying Whole Numbers
Stem: The provider orders cefazolin 750 mg IV. The vial label
reads 250 mg per 5 mL. How many milliliters should the nurse
prepare?
A. 7.5 mL
B. 15 mL
C. 10 mL
D. 30 mL
Correct answer: B. 15 mL
Rationale — Correct (B): Convert by setting a ratio: 250 mg → 5
mL. For 750 mg: (750 mg) × (5 mL / 250 mg) = 3 × 5 mL = 15 mL.
Units cancel correctly (mg). Prepare 15 mL.

,Rationale — A: 7.5 mL results from dividing 750 by 100 (or
halving the correct volume); this is a decimal-placement error.
Rationale — C: 10 mL implies using 250 mg per 25 mL or
incorrect multiplication—mathematically inconsistent with the
vial concentration.
Rationale — D: 30 mL is double the correct volume and
indicates misreading the ratio (e.g., multiplying by 2).
Teaching point: Use ratio: desired × (volume / concentration)
and check unit cancellation.
Citation: Buchholz, S. (2024). Henke’s Med-Math: Dosage
Calculation, Preparation & Administration (10th ed.). Ch. 1.


2. Reference: Ch. 1 — Multiplying Whole Numbers
Stem: An order requests digoxin 200 mg orally. Available tablets
are 50 mg each. How many tablets will the nurse give?
A. 2 tablets
B. 3 tablets
C. 4 tablets
D. 5 tablets
Correct answer: C. 4 tablets
Rationale — Correct (C): Number of tablets = desired dose /
tablet strength = 200 mg ÷ 50 mg = 4 tablets. Units (mg) cancel.
Rationale — A: 2 tablets would deliver 100 mg (under-dose)
and indicates halving the calculation.
Rationale — B: 3 tablets gives 150 mg; likely from misdividing

,200 by 75 or rounding incorrectly.
Rationale — D: 5 tablets gives 250 mg (over-dose) and reflects
using wrong divisor (40 mg/tablet).
Teaching point: Always divide desired dose by single-tablet
strength; verify units cancel.
Citation: Buchholz, S. (2024). Henke’s Med-Math… Ch. 1.


3. Reference: Ch. 1 — Multiplying Whole Numbers
Stem: A medication vial contains 500 mg in 2 mL. The order is
for 125 mg IV. How many milliliters should the nurse draw up?
A. 0.25 mL
B. 0.5 mL
C. 1 mL
D. 2 mL
Correct answer: B. 0.5 mL
Rationale — Correct (B): Use concentration ratio: 500 mg → 2
mL, so 125 mg × (2 mL / 500 mg) = 0.5 mL. Units cancel (mg).
Rationale — A: 0.25 mL would be obtained by an error halving
again (e.g., 125/1000).
Rationale — C: 1 mL corresponds to 250 mg, double the
ordered dose.
Rationale — D: 2 mL equals the full 500 mg vial—administering
this would cause a 4× overdose.

, Teaching point: Multiply desired dose by (mL per mg) to get
correct volume; cancel units.
Citation: Buchholz, S. (2024). Henke’s Med-Math… Ch. 1.


4. Reference: Ch. 1 — Dividing Whole Numbers
Stem: A pharmacist dispenses 1 g (1000 mg) of medication in a
10 mL vial. The provider orders 250 mg IV. How many milliliters
will the nurse administer?
A. 0.25 mL
B. 0.5 mL
C. 2.5 mL
D. 25 mL
Correct answer: C. 2.5 mL
Rationale — Correct (C): Concentration = 1000 mg / 10 mL =
100 mg/mL. Volume = desired dose ÷ concentration = 250 mg ÷
100 mg/mL = 2.5 mL.
Rationale — A: 0.25 mL is a decimal place error (would deliver
25 mg).
Rationale — B: 0.5 mL would deliver 50 mg (incorrect division).
Rationale — D: 25 mL would deliver 2500 mg (10× overdose).
Teaching point: Convert units first (g → mg), then divide desired
dose by mg/mL concentration.
Citation: Buchholz, S. (2024). Henke’s Med-Math… Ch. 1.