HENKE'S MED-MATH
DOSAGE CALCULATION, PREPARATION
& ADMINISTRATION
10TH EDITION
• AUTHOR(S)SUSAN BUCHHOLZ
TEST BANK
1) Ch. 1 — Multiplying Whole Numbers
Stem: A physician orders acetaminophen 3 tablets for
postoperative pain. Each tablet contains 250 mg. How many
milligrams of acetaminophen will the patient receive per dose?
A. 500 mg
B. 750 mg
C. 1,000 mg
D. 1,250 mg
Correct Answer: B. 750 mg
Rationale — Correct (B): Multiply tablets × mg per tablet: 3 ×
250 mg = 750 mg. This uses simple whole-number
,multiplication to calculate total drug taken.
Rationale — A: 500 mg represents a calculation error as if 2
tablets were given (2 × 250 mg). This underdoses the patient.
Rationale — C: 1,000 mg is 4 × 250 mg; this overestimates by
one tablet.
Rationale — D: 1,250 mg is 5 × 250 mg and is not supported by
the order.
Teaching Point: Multiply number of units by strength per unit to
find total dose.
Citation: Buchholz, S. (2024). Henke’s Med-Math: Dosage
Calculation, Preparation & Administration (10th ed.). Ch. 1.
2) Ch. 1 — Dividing Whole Numbers
Stem: An IV bag contains 1,200 mL normal saline. The order is
to infuse the bag evenly over 8 hours. What infusion rate
(mL/hr) should the nurse program on the pump?
A. 100 mL/hr
B. 150 mL/hr
C. 200 mL/hr
D. 300 mL/hr
Correct Answer: B. 150 mL/hr
Rationale — Correct (B): Divide total volume by hours: 1,200
mL ÷ 8 hr = 150 mL/hr. This uses whole-number division to
determine hourly rate.
Rationale — A: 100 mL/hr results from dividing by 12 (1,200 ÷
,12) and would prolong therapy.
Rationale — C: 200 mL/hr equals 1,200 ÷ 6; this would finish
the bag in 6 hours (too fast).
Rationale — D: 300 mL/hr would finish in 4 hours and risks fluid
overload.
Teaching Point: Hourly rate = total volume ÷ total hours.
Citation: Buchholz, S. (2024). Henke’s Med-Math. Ch. 1.
3) Ch. 1 — Fractions
Stem: The provider orders ¾ of a 160-mg tablet of medication
(the tablet is scored). How many milligrams will the patient
receive?
A. 40 mg
B. 80 mg
C. 120 mg
D. 140 mg
Correct Answer: C. 120 mg
Rationale — Correct (C): Multiply fraction × tablet strength:
(3/4) × 160 mg = 120 mg. Use fraction conversion to decimal if
preferred: 0.75 × 160 = 120 mg.
Rationale — A: 40 mg is (1/4) × 160 mg (wrong fraction).
Rationale — B: 80 mg equals (1/2) × 160 mg; that is ½ not ¾.
Rationale — D: 140 mg is an incorrect arithmetic result (160 −
20), not based on ¾.
, Teaching Point: Multiply fraction by total strength to get partial-
tablet dose.
Citation: Buchholz, S. (2024). Henke’s Med-Math. Ch. 1.
4) Ch. 1 — Decimals
Stem: A provider orders drug X at 0.5 mg/kg IV once. The
patient weighs 72.5 kg. What dose in milligrams should the
nurse prepare? (Report to two decimal places.)
A. 36.25 mg
B. 35.0 mg
C. 72.5 mg
D. 0.36 mg
Correct Answer: A. 36.25 mg
Rationale — Correct (A): Multiply weight × dose per kg: 72.5 kg
× 0.5 mg/kg = 36.25 mg. Use decimal multiplication and report
to appropriate precision.
Rationale — B: 35.0 mg underestimates the dose and likely
results from mis-multiplying 70 × 0.5.
Rationale — C: 72.5 mg would be 1.0 mg/kg, not the ordered
0.5 mg/kg.
Rationale — D: 0.36 mg results from incorrect placement of the
decimal.
Teaching Point: Multiply weight (kg) by mg/kg; preserve
decimal precision.
Citation: Buchholz, S. (2024). Henke’s Med-Math. Ch. 1.
DOSAGE CALCULATION, PREPARATION
& ADMINISTRATION
10TH EDITION
• AUTHOR(S)SUSAN BUCHHOLZ
TEST BANK
1) Ch. 1 — Multiplying Whole Numbers
Stem: A physician orders acetaminophen 3 tablets for
postoperative pain. Each tablet contains 250 mg. How many
milligrams of acetaminophen will the patient receive per dose?
A. 500 mg
B. 750 mg
C. 1,000 mg
D. 1,250 mg
Correct Answer: B. 750 mg
Rationale — Correct (B): Multiply tablets × mg per tablet: 3 ×
250 mg = 750 mg. This uses simple whole-number
,multiplication to calculate total drug taken.
Rationale — A: 500 mg represents a calculation error as if 2
tablets were given (2 × 250 mg). This underdoses the patient.
Rationale — C: 1,000 mg is 4 × 250 mg; this overestimates by
one tablet.
Rationale — D: 1,250 mg is 5 × 250 mg and is not supported by
the order.
Teaching Point: Multiply number of units by strength per unit to
find total dose.
Citation: Buchholz, S. (2024). Henke’s Med-Math: Dosage
Calculation, Preparation & Administration (10th ed.). Ch. 1.
2) Ch. 1 — Dividing Whole Numbers
Stem: An IV bag contains 1,200 mL normal saline. The order is
to infuse the bag evenly over 8 hours. What infusion rate
(mL/hr) should the nurse program on the pump?
A. 100 mL/hr
B. 150 mL/hr
C. 200 mL/hr
D. 300 mL/hr
Correct Answer: B. 150 mL/hr
Rationale — Correct (B): Divide total volume by hours: 1,200
mL ÷ 8 hr = 150 mL/hr. This uses whole-number division to
determine hourly rate.
Rationale — A: 100 mL/hr results from dividing by 12 (1,200 ÷
,12) and would prolong therapy.
Rationale — C: 200 mL/hr equals 1,200 ÷ 6; this would finish
the bag in 6 hours (too fast).
Rationale — D: 300 mL/hr would finish in 4 hours and risks fluid
overload.
Teaching Point: Hourly rate = total volume ÷ total hours.
Citation: Buchholz, S. (2024). Henke’s Med-Math. Ch. 1.
3) Ch. 1 — Fractions
Stem: The provider orders ¾ of a 160-mg tablet of medication
(the tablet is scored). How many milligrams will the patient
receive?
A. 40 mg
B. 80 mg
C. 120 mg
D. 140 mg
Correct Answer: C. 120 mg
Rationale — Correct (C): Multiply fraction × tablet strength:
(3/4) × 160 mg = 120 mg. Use fraction conversion to decimal if
preferred: 0.75 × 160 = 120 mg.
Rationale — A: 40 mg is (1/4) × 160 mg (wrong fraction).
Rationale — B: 80 mg equals (1/2) × 160 mg; that is ½ not ¾.
Rationale — D: 140 mg is an incorrect arithmetic result (160 −
20), not based on ¾.
, Teaching Point: Multiply fraction by total strength to get partial-
tablet dose.
Citation: Buchholz, S. (2024). Henke’s Med-Math. Ch. 1.
4) Ch. 1 — Decimals
Stem: A provider orders drug X at 0.5 mg/kg IV once. The
patient weighs 72.5 kg. What dose in milligrams should the
nurse prepare? (Report to two decimal places.)
A. 36.25 mg
B. 35.0 mg
C. 72.5 mg
D. 0.36 mg
Correct Answer: A. 36.25 mg
Rationale — Correct (A): Multiply weight × dose per kg: 72.5 kg
× 0.5 mg/kg = 36.25 mg. Use decimal multiplication and report
to appropriate precision.
Rationale — B: 35.0 mg underestimates the dose and likely
results from mis-multiplying 70 × 0.5.
Rationale — C: 72.5 mg would be 1.0 mg/kg, not the ordered
0.5 mg/kg.
Rationale — D: 0.36 mg results from incorrect placement of the
decimal.
Teaching Point: Multiply weight (kg) by mg/kg; preserve
decimal precision.
Citation: Buchholz, S. (2024). Henke’s Med-Math. Ch. 1.
