HENKE'S MED-MATH
DOSAGE CALCULATION, PREPARATION
& ADMINISTRATION
10TH EDITION
• AUTHOR(S)SUSAN BUCHHOLZ
TEST BANK
1
Reference
Ch. 1 — Multiplying Whole Numbers
Question stem
A provider orders 1,500 mg of acetaminophen PO. Available
tablets are 500 mg each. How many tablets should the nurse
administer? Calculate and confirm safe dosing.
Options
A. 2 tablets
B. 3 tablets
,C. 4 tablets
D. 1.5 tablets
Correct answer
B. 3 tablets
Rationales
Correct (B): 1,500 mg ÷ 500 mg/tablet = 3 tablets. Step: divide
total ordered dose by strength per tablet. This yields exactly 3
tablets, matching the ordered dose and avoiding under- or
overdosing.
A: 2 tablets = 1,000 mg (under-dose). The error is dividing
incorrectly or dropping a digit; it would provide only two-thirds
of the ordered dose.
C: 4 tablets = 2,000 mg (overdose). The error is multiplying
instead of dividing or choosing the next whole tablet without
calculation. This could exceed safe limits.
D: 1.5 tablets = 750 mg (under-dose). The error is halving the
required dose or misreading the order; giving half a tablet when
three are needed would be insufficient.
Teaching point
Always divide total dose by per-tablet strength; confirm whole-
tablet feasibility and safety.
Citation
Buchholz, S. (2024). Henke’s Med-Math: Dosage Calculation,
Preparation & Administration (10th ed.). Ch. 1.
,2
Reference
Ch. 1 — Dividing Whole Numbers
Question stem
An IV medication of 180 mL must be infused evenly over 3
hours. What infusion rate (mL/hr) should the nurse set on the
infusion pump? Calculate and state the correct rate.
Options
A. 30 mL/hr
B. 60 mL/hr
C. 90 mL/hr
D. 45 mL/hr
Correct answer
B. 60 mL/hr
Rationales
Correct (B): 180 mL ÷ 3 hr = 60 mL/hr. Divide total volume by
total hours to obtain mL per hour—this is the pump setting.
A: 30 mL/hr would infuse 90 mL in 3 hours (under-infusion).
Error: dividing by 6 instead of 3 or halving result.
C: 90 mL/hr would infuse 270 mL in 3 hours (over-infusion).
Error: dividing incorrectly or using 2 hr instead of 3 hr. Could
cause fluid overload.
D: 45 mL/hr would infuse 135 mL in 3 hours (under-infusion).
Error: wrong division (180 ÷ 4) or decimal misplacement.
, Teaching point
Divide total volume by time (hours) to set mL/hr; double-check
units before programming pump.
Citation
Buchholz, S. (2024). Henke’s Med-Math: Dosage Calculation,
Preparation & Administration (10th ed.). Ch. 1.
3
Reference
Ch. 1 — Fractions
Question stem
A provider orders three-quarters (¾) of a 400-mg tablet. How
many milligrams should the nurse administer? Show the
fraction multiplication.
Options
A. 100 mg
B. 300 mg
C. 200 mg
D. 350 mg
Correct answer
B. 300 mg
Rationales
Correct (B): ¾ × 400 mg = (3 × 400) ÷ 4 = 1,200 ÷ 4 = 300 mg.
Convert the fraction to multiplication and divide by the
DOSAGE CALCULATION, PREPARATION
& ADMINISTRATION
10TH EDITION
• AUTHOR(S)SUSAN BUCHHOLZ
TEST BANK
1
Reference
Ch. 1 — Multiplying Whole Numbers
Question stem
A provider orders 1,500 mg of acetaminophen PO. Available
tablets are 500 mg each. How many tablets should the nurse
administer? Calculate and confirm safe dosing.
Options
A. 2 tablets
B. 3 tablets
,C. 4 tablets
D. 1.5 tablets
Correct answer
B. 3 tablets
Rationales
Correct (B): 1,500 mg ÷ 500 mg/tablet = 3 tablets. Step: divide
total ordered dose by strength per tablet. This yields exactly 3
tablets, matching the ordered dose and avoiding under- or
overdosing.
A: 2 tablets = 1,000 mg (under-dose). The error is dividing
incorrectly or dropping a digit; it would provide only two-thirds
of the ordered dose.
C: 4 tablets = 2,000 mg (overdose). The error is multiplying
instead of dividing or choosing the next whole tablet without
calculation. This could exceed safe limits.
D: 1.5 tablets = 750 mg (under-dose). The error is halving the
required dose or misreading the order; giving half a tablet when
three are needed would be insufficient.
Teaching point
Always divide total dose by per-tablet strength; confirm whole-
tablet feasibility and safety.
Citation
Buchholz, S. (2024). Henke’s Med-Math: Dosage Calculation,
Preparation & Administration (10th ed.). Ch. 1.
,2
Reference
Ch. 1 — Dividing Whole Numbers
Question stem
An IV medication of 180 mL must be infused evenly over 3
hours. What infusion rate (mL/hr) should the nurse set on the
infusion pump? Calculate and state the correct rate.
Options
A. 30 mL/hr
B. 60 mL/hr
C. 90 mL/hr
D. 45 mL/hr
Correct answer
B. 60 mL/hr
Rationales
Correct (B): 180 mL ÷ 3 hr = 60 mL/hr. Divide total volume by
total hours to obtain mL per hour—this is the pump setting.
A: 30 mL/hr would infuse 90 mL in 3 hours (under-infusion).
Error: dividing by 6 instead of 3 or halving result.
C: 90 mL/hr would infuse 270 mL in 3 hours (over-infusion).
Error: dividing incorrectly or using 2 hr instead of 3 hr. Could
cause fluid overload.
D: 45 mL/hr would infuse 135 mL in 3 hours (under-infusion).
Error: wrong division (180 ÷ 4) or decimal misplacement.
, Teaching point
Divide total volume by time (hours) to set mL/hr; double-check
units before programming pump.
Citation
Buchholz, S. (2024). Henke’s Med-Math: Dosage Calculation,
Preparation & Administration (10th ed.). Ch. 1.
3
Reference
Ch. 1 — Fractions
Question stem
A provider orders three-quarters (¾) of a 400-mg tablet. How
many milligrams should the nurse administer? Show the
fraction multiplication.
Options
A. 100 mg
B. 300 mg
C. 200 mg
D. 350 mg
Correct answer
B. 300 mg
Rationales
Correct (B): ¾ × 400 mg = (3 × 400) ÷ 4 = 1,200 ÷ 4 = 300 mg.
Convert the fraction to multiplication and divide by the
