HENKE'S MED-MATH
DOSAGE CALCULATION, PREPARATION
& ADMINISTRATION
10TH EDITION
• AUTHOR(S)SUSAN BUCHHOLZ
TEST BANK
1)
Reference
Ch. 1 — Multiplying Whole Numbers
Stem
A pediatric provider orders acetaminophen 240 mg by mouth.
The unit-dose syringes on the med cart contain acetaminophen
80 mg per 1 mL. The nurse must prepare the single ordered
dose. How many mL should the nurse draw up?
Options
A. 2.0 mL
,B. 2.5 mL
C. 3.0 mL
D. 1.5 mL
Correct Answer
A. 2.0 mL
Rationales
Correct (A): Required volume = desired mg ÷ concentration
mg/mL = 240 mg ÷ 80 mg/mL = 3.0? Wait — recalc: 240 ÷ 80 =
3. Oops error — must correct.
Fix: Correct calculation yields 3.0 mL. Therefore the correct
answer should be C. 3.0 mL. (See corrected option and rationale
below.)
Corrected Correct Answer
C. 3.0 mL
Correct (C) Rationale (3–4 sentences):
Desired dose ÷ concentration = 240 mg ÷ 80 mg per mL = 3 mL.
Step-by-step: divide 240 by 80 (240 ÷ 80 = 3). Draw 3.0 mL to
deliver 240 mg. This follows simple multiplication/division
arithmetic taught in Ch.1.
Incorrect Options:
A. 2.0 mL — This results from dividing by 120 instead of 80 (240
÷ 120 = 2); a wrong concentration used leads to underdosing.
B. 2.5 mL — Likely calculation error or rounding from an
incorrect intermediate value; underdoses patient.
,D. 1.5 mL — Reflects halving the needed volume; would deliver
only 120 mg, risking inadequate analgesia/antipyresis.
Teaching Point
Divide desired dose by concentration (mg/mL) — keep units
consistent.
Citation
Buchholz, S. (2024). Henke’s Med-Math: Dosage Calculation,
Preparation & Administration (10th ed.). Ch. 1.
2)
Reference
Ch. 1 — Dividing Whole Numbers
Stem
An order reads: give 1500 mL of maintenance IV fluid evenly
over 12 hours. The infusion pump displays mL/hour. What rate
(mL/hr) should the nurse program?
Options
A. 100 mL/hr
B. 125 mL/hr
C. 150 mL/hr
D. 200 mL/hr
Correct Answer
B. 125 mL/hr
, Rationales
Correct (B): Rate = total volume ÷ total hours = 1500 mL ÷ 12 hr
= 125 mL/hr. Step-by-step division yields 125 exactly. Program
pump to 125 mL/hr.
Incorrect (A): 100 mL/hr = result of dividing by 15 hrs (1500 ÷
15), wrong time interval; would underinfuse.
Incorrect (C): 150 mL/hr = result of dividing by 10 hrs (1500 ÷
10); would overinfuse.
Incorrect (D): 200 mL/hr = result of dividing by 7.5 hrs; gross
overinfusion; risk of fluid overload.
Teaching Point
Divide total volume by total time in hours for mL/hr rates.
Citation
Buchholz, S. (2024). Henke’s Med-Math: Dosage Calculation,
Preparation & Administration (10th ed.). Ch. 1.
3)
Reference
Ch. 1 — Fractions
Stem
A provider orders ⅜ teaspoon of cough syrup for a child. The
unit-dose cup measures in mL; 1 teaspoon = 5 mL. How many
milliliters should the nurse administer?
Options
A. 1.25 mL
DOSAGE CALCULATION, PREPARATION
& ADMINISTRATION
10TH EDITION
• AUTHOR(S)SUSAN BUCHHOLZ
TEST BANK
1)
Reference
Ch. 1 — Multiplying Whole Numbers
Stem
A pediatric provider orders acetaminophen 240 mg by mouth.
The unit-dose syringes on the med cart contain acetaminophen
80 mg per 1 mL. The nurse must prepare the single ordered
dose. How many mL should the nurse draw up?
Options
A. 2.0 mL
,B. 2.5 mL
C. 3.0 mL
D. 1.5 mL
Correct Answer
A. 2.0 mL
Rationales
Correct (A): Required volume = desired mg ÷ concentration
mg/mL = 240 mg ÷ 80 mg/mL = 3.0? Wait — recalc: 240 ÷ 80 =
3. Oops error — must correct.
Fix: Correct calculation yields 3.0 mL. Therefore the correct
answer should be C. 3.0 mL. (See corrected option and rationale
below.)
Corrected Correct Answer
C. 3.0 mL
Correct (C) Rationale (3–4 sentences):
Desired dose ÷ concentration = 240 mg ÷ 80 mg per mL = 3 mL.
Step-by-step: divide 240 by 80 (240 ÷ 80 = 3). Draw 3.0 mL to
deliver 240 mg. This follows simple multiplication/division
arithmetic taught in Ch.1.
Incorrect Options:
A. 2.0 mL — This results from dividing by 120 instead of 80 (240
÷ 120 = 2); a wrong concentration used leads to underdosing.
B. 2.5 mL — Likely calculation error or rounding from an
incorrect intermediate value; underdoses patient.
,D. 1.5 mL — Reflects halving the needed volume; would deliver
only 120 mg, risking inadequate analgesia/antipyresis.
Teaching Point
Divide desired dose by concentration (mg/mL) — keep units
consistent.
Citation
Buchholz, S. (2024). Henke’s Med-Math: Dosage Calculation,
Preparation & Administration (10th ed.). Ch. 1.
2)
Reference
Ch. 1 — Dividing Whole Numbers
Stem
An order reads: give 1500 mL of maintenance IV fluid evenly
over 12 hours. The infusion pump displays mL/hour. What rate
(mL/hr) should the nurse program?
Options
A. 100 mL/hr
B. 125 mL/hr
C. 150 mL/hr
D. 200 mL/hr
Correct Answer
B. 125 mL/hr
, Rationales
Correct (B): Rate = total volume ÷ total hours = 1500 mL ÷ 12 hr
= 125 mL/hr. Step-by-step division yields 125 exactly. Program
pump to 125 mL/hr.
Incorrect (A): 100 mL/hr = result of dividing by 15 hrs (1500 ÷
15), wrong time interval; would underinfuse.
Incorrect (C): 150 mL/hr = result of dividing by 10 hrs (1500 ÷
10); would overinfuse.
Incorrect (D): 200 mL/hr = result of dividing by 7.5 hrs; gross
overinfusion; risk of fluid overload.
Teaching Point
Divide total volume by total time in hours for mL/hr rates.
Citation
Buchholz, S. (2024). Henke’s Med-Math: Dosage Calculation,
Preparation & Administration (10th ed.). Ch. 1.
3)
Reference
Ch. 1 — Fractions
Stem
A provider orders ⅜ teaspoon of cough syrup for a child. The
unit-dose cup measures in mL; 1 teaspoon = 5 mL. How many
milliliters should the nurse administer?
Options
A. 1.25 mL
