HENKE'S MED-MATH
DOSAGE CALCULATION, PREPARATION
& ADMINISTRATION
10TH EDITION
• AUTHOR(S)SUSAN BUCHHOLZ
TEST BANK
Reference
Ch. 1 — Dividing Whole Numbers
Question Stem
A provider orders acetaminophen 1,200 mg PO for a
postoperative patient. The medication available is
acetaminophen 300 mg tablets. How many whole tablets
should the nurse administer per dose?
Options
A. 3 tablets
B. 4 tablets
C. 5 tablets
D. 6 tablets
,Correct Answer
B. 4 tablets
Rationales
Correct Option (B): 1,200 mg ÷ 300 mg/tablet = 4 tablets. Divide
the ordered dose by the strength per tablet to determine
tablets needed. Giving 4 tablets provides the exact ordered
1,200 mg and follows safe dose verification principles in Henke’s
method.
Option A (3 tablets): 3 × 300 mg = 900 mg; underdosing by 300
mg. This error comes from dividing incorrectly or truncating the
quotient.
Option C (5 tablets): 5 × 300 mg = 1,500 mg; overdosing by 300
mg. This reflects adding an extra tablet instead of matching the
quotient.
Option D (6 tablets): 6 × 300 mg = 1,800 mg; large overdose.
Likely a multiplication error or misreading the ordered dose.
Teaching Point
Divide ordered dose by strength per unit; confirm whole/tablet
requirements.
Citation
Buchholz, S. (2024). Henke’s Med-Math: Dosage Calculation,
Preparation & Administration (10th ed.). Ch. 1.
2.
,Reference
Ch. 1 — Multiplying Whole Numbers
Question Stem
A provider prescribes heparin flush solution: 10 mL per lumen
for a triple-lumen central line. The pharmacy supplies single-use
vials of 10 mL each. How many vials are needed to flush all
three lumens once?
Options
A. 1 vial
B. 2 vials
C. 3 vials
D. 30 vials
Correct Answer
C. 3 vials
Rationales
Correct Option (C): Required volume = 10 mL × 3 lumens = 30
mL total. Each vial is 10 mL; 30 mL ÷ 10 mL/vial = 3 vials.
Multiply lumen count by per-lumen volume, then divide by vial
volume to confirm vials needed.
Option A (1 vial): 1 × 10 mL = 10 mL; insufficient volume to flush
three lumens. This reflects failing to multiply by number of
lumens.
Option B (2 vials): 2 × 10 mL = 20 mL; still insufficient. Common
error: undercounting lumens or arithmetic slip.
Option D (30 vials): Misplaced decimal or interpreting 30 mL as
30 vials — a magnitude error.
, Teaching Point
Multiply per-unit volume by units required, then divide by
supply size to find containers needed.
Citation
Buchholz, S. (2024). Henke’s Med-Math: Dosage Calculation,
Preparation & Administration (10th ed.). Ch. 1.
3.
Reference
Ch. 1 — Fractions
Question Stem
A pediatric provider orders ¾ of a 200 mg chewable tablet for a
child. Each tablet contains 200 mg. How many milligrams should
the nurse administer?
Options
A. 50 mg
B. 100 mg
C. 150 mg
D. 175 mg
Correct Answer
C. 150 mg
Rationales
Correct Option (C): (3/4) × 200 mg = 600/4 = 150 mg. Multiply
the fraction by the tablet strength to get the administered dose.
DOSAGE CALCULATION, PREPARATION
& ADMINISTRATION
10TH EDITION
• AUTHOR(S)SUSAN BUCHHOLZ
TEST BANK
Reference
Ch. 1 — Dividing Whole Numbers
Question Stem
A provider orders acetaminophen 1,200 mg PO for a
postoperative patient. The medication available is
acetaminophen 300 mg tablets. How many whole tablets
should the nurse administer per dose?
Options
A. 3 tablets
B. 4 tablets
C. 5 tablets
D. 6 tablets
,Correct Answer
B. 4 tablets
Rationales
Correct Option (B): 1,200 mg ÷ 300 mg/tablet = 4 tablets. Divide
the ordered dose by the strength per tablet to determine
tablets needed. Giving 4 tablets provides the exact ordered
1,200 mg and follows safe dose verification principles in Henke’s
method.
Option A (3 tablets): 3 × 300 mg = 900 mg; underdosing by 300
mg. This error comes from dividing incorrectly or truncating the
quotient.
Option C (5 tablets): 5 × 300 mg = 1,500 mg; overdosing by 300
mg. This reflects adding an extra tablet instead of matching the
quotient.
Option D (6 tablets): 6 × 300 mg = 1,800 mg; large overdose.
Likely a multiplication error or misreading the ordered dose.
Teaching Point
Divide ordered dose by strength per unit; confirm whole/tablet
requirements.
Citation
Buchholz, S. (2024). Henke’s Med-Math: Dosage Calculation,
Preparation & Administration (10th ed.). Ch. 1.
2.
,Reference
Ch. 1 — Multiplying Whole Numbers
Question Stem
A provider prescribes heparin flush solution: 10 mL per lumen
for a triple-lumen central line. The pharmacy supplies single-use
vials of 10 mL each. How many vials are needed to flush all
three lumens once?
Options
A. 1 vial
B. 2 vials
C. 3 vials
D. 30 vials
Correct Answer
C. 3 vials
Rationales
Correct Option (C): Required volume = 10 mL × 3 lumens = 30
mL total. Each vial is 10 mL; 30 mL ÷ 10 mL/vial = 3 vials.
Multiply lumen count by per-lumen volume, then divide by vial
volume to confirm vials needed.
Option A (1 vial): 1 × 10 mL = 10 mL; insufficient volume to flush
three lumens. This reflects failing to multiply by number of
lumens.
Option B (2 vials): 2 × 10 mL = 20 mL; still insufficient. Common
error: undercounting lumens or arithmetic slip.
Option D (30 vials): Misplaced decimal or interpreting 30 mL as
30 vials — a magnitude error.
, Teaching Point
Multiply per-unit volume by units required, then divide by
supply size to find containers needed.
Citation
Buchholz, S. (2024). Henke’s Med-Math: Dosage Calculation,
Preparation & Administration (10th ed.). Ch. 1.
3.
Reference
Ch. 1 — Fractions
Question Stem
A pediatric provider orders ¾ of a 200 mg chewable tablet for a
child. Each tablet contains 200 mg. How many milligrams should
the nurse administer?
Options
A. 50 mg
B. 100 mg
C. 150 mg
D. 175 mg
Correct Answer
C. 150 mg
Rationales
Correct Option (C): (3/4) × 200 mg = 600/4 = 150 mg. Multiply
the fraction by the tablet strength to get the administered dose.
