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 provider orders 3 tablets of amoxicillin every 8 hours
for 5 days. Each tablet is 250 mg. How many milligrams of
amoxicillin will the patient receive in total over the 5-day
course? (Show total mg.)
A. 9,000 mg
B. 11,250 mg
C. 15,000 mg
D. 18,000 mg
Correct Answer: B. 11,250 mg
,Rationale — Correct: 3 tablets × 250 mg = 750 mg per dose.
There are 3 doses/day (every 8 hours) → 750 mg × 3 = 2,250
mg/day. Over 5 days: 2,250 mg × 5 = 11,250 mg. Multiplying
whole numbers stepwise yields the total.
Rationale — A: 9,000 mg assumes 3 doses/day × 3 days
(incorrect days) or wrong multiplication; it's an
underestimation.
Rationale — C: 15,000 mg equals 3,000 mg/day × 5 days —
implies 4 tablets/dose instead of 3.
Rationale — D: 18,000 mg is mathematically inconsistent with
given tablet strength and dosing frequency.
Teaching point: Multiply sequentially: dose × frequency/day ×
number of days.
Citation: Buchholz, S. (2023). Henke’s Med-Math: Dosage
Calculation, Preparation & Administration (10th ed.). Ch. 1.
2)
Reference: Ch. 1 — Dividing Whole Numbers
Stem: A vial contains 2,400 mg of an antibiotic in 12 mL. The
nurse needs to prepare 200 mg per syringe for each of 8
patients. How many milliliters should the nurse draw up for one
200-mg syringe? (Round to two decimal places if needed.)
A. 1.00 mL
B. 0.83 mL
,C. 1.20 mL
D. 0.67 mL
Correct Answer: B. 0.83 mL
Rationale — Correct: Concentration = 2,400 mg / 12 mL = 200
mg/mL. For 200 mg: 200 mg ÷ (200 mg/mL) = 1.00 mL. Wait —
check math: actually 2,400/12 = 200 mg/mL → 200 mg needs
1.00 mL. (Correct answer should be A: 1.00 mL.)
[Correction applied — final answer A below.]
Correct Answer (revised): A. 1.00 mL
Rationale — Correct (revised): Find mg per mL: 2,400 mg ÷ 12
mL = 200 mg/mL. Required volume = desired dose ÷
concentration = 200 mg ÷ 200 mg/mL = 1.00 mL.
Rationale — B: 0.83 mL would come from mistakenly dividing
200 by 240 (not by 200).
Rationale — C: 1.20 mL results from using wrong concentration
(e.g., 166.7 mg/mL).
Rationale — D: 0.67 mL underestimates volume due to
decimal-placement error.
Teaching point: Divide total drug by total volume to get mg/mL,
then desired ÷ concentration.
Citation: Buchholz, S. (2023). Henke’s Med-Math... Ch. 1.
3)
Reference: Ch. 1 — Fractions (Reducing Fractions)
, Stem: A patient must ingest 3/4 (three quarters) of a 1,200-mL
enteral feeding. How many milliliters remain to be given if the
patient already received 350 mL? (Answer in mL.)
A. 550 mL
B. 400 mL
C. 500 mL
D. 600 mL
Correct Answer: A. 550 mL
Rationale — Correct: Total ordered = (3/4) × 1,200 mL = 900
mL. Received 350 mL, so remaining = 900 − 350 = 550 mL.
Fraction multiplication then subtraction yields remaining
volume.
Rationale — B: 400 mL assumes total was 750 mL (incorrect
fraction of total).
Rationale — C: 500 mL results from miscalculating 900 − 400
instead of using actual received amount.
Rationale — D: 600 mL equals 900 − 300; misread amount
given.
Teaching point: Multiply fraction by total volume before
subtracting received amounts.
Citation: Buchholz, S. (2023). Henke’s Med-Math... Ch. 1.
4)
Reference: Ch. 1 — Types of Fractions (Improper & Mixed
Numbers)
DOSAGE CALCULATION, PREPARATION
& ADMINISTRATION
10TH EDITION
• AUTHOR(S)SUSAN BUCHHOLZ
TEST BANK
1)
Reference: Ch. 1 — Multiplying Whole Numbers
Stem: A provider orders 3 tablets of amoxicillin every 8 hours
for 5 days. Each tablet is 250 mg. How many milligrams of
amoxicillin will the patient receive in total over the 5-day
course? (Show total mg.)
A. 9,000 mg
B. 11,250 mg
C. 15,000 mg
D. 18,000 mg
Correct Answer: B. 11,250 mg
,Rationale — Correct: 3 tablets × 250 mg = 750 mg per dose.
There are 3 doses/day (every 8 hours) → 750 mg × 3 = 2,250
mg/day. Over 5 days: 2,250 mg × 5 = 11,250 mg. Multiplying
whole numbers stepwise yields the total.
Rationale — A: 9,000 mg assumes 3 doses/day × 3 days
(incorrect days) or wrong multiplication; it's an
underestimation.
Rationale — C: 15,000 mg equals 3,000 mg/day × 5 days —
implies 4 tablets/dose instead of 3.
Rationale — D: 18,000 mg is mathematically inconsistent with
given tablet strength and dosing frequency.
Teaching point: Multiply sequentially: dose × frequency/day ×
number of days.
Citation: Buchholz, S. (2023). Henke’s Med-Math: Dosage
Calculation, Preparation & Administration (10th ed.). Ch. 1.
2)
Reference: Ch. 1 — Dividing Whole Numbers
Stem: A vial contains 2,400 mg of an antibiotic in 12 mL. The
nurse needs to prepare 200 mg per syringe for each of 8
patients. How many milliliters should the nurse draw up for one
200-mg syringe? (Round to two decimal places if needed.)
A. 1.00 mL
B. 0.83 mL
,C. 1.20 mL
D. 0.67 mL
Correct Answer: B. 0.83 mL
Rationale — Correct: Concentration = 2,400 mg / 12 mL = 200
mg/mL. For 200 mg: 200 mg ÷ (200 mg/mL) = 1.00 mL. Wait —
check math: actually 2,400/12 = 200 mg/mL → 200 mg needs
1.00 mL. (Correct answer should be A: 1.00 mL.)
[Correction applied — final answer A below.]
Correct Answer (revised): A. 1.00 mL
Rationale — Correct (revised): Find mg per mL: 2,400 mg ÷ 12
mL = 200 mg/mL. Required volume = desired dose ÷
concentration = 200 mg ÷ 200 mg/mL = 1.00 mL.
Rationale — B: 0.83 mL would come from mistakenly dividing
200 by 240 (not by 200).
Rationale — C: 1.20 mL results from using wrong concentration
(e.g., 166.7 mg/mL).
Rationale — D: 0.67 mL underestimates volume due to
decimal-placement error.
Teaching point: Divide total drug by total volume to get mg/mL,
then desired ÷ concentration.
Citation: Buchholz, S. (2023). Henke’s Med-Math... Ch. 1.
3)
Reference: Ch. 1 — Fractions (Reducing Fractions)
, Stem: A patient must ingest 3/4 (three quarters) of a 1,200-mL
enteral feeding. How many milliliters remain to be given if the
patient already received 350 mL? (Answer in mL.)
A. 550 mL
B. 400 mL
C. 500 mL
D. 600 mL
Correct Answer: A. 550 mL
Rationale — Correct: Total ordered = (3/4) × 1,200 mL = 900
mL. Received 350 mL, so remaining = 900 − 350 = 550 mL.
Fraction multiplication then subtraction yields remaining
volume.
Rationale — B: 400 mL assumes total was 750 mL (incorrect
fraction of total).
Rationale — C: 500 mL results from miscalculating 900 − 400
instead of using actual received amount.
Rationale — D: 600 mL equals 900 − 300; misread amount
given.
Teaching point: Multiply fraction by total volume before
subtracting received amounts.
Citation: Buchholz, S. (2023). Henke’s Med-Math... Ch. 1.
4)
Reference: Ch. 1 — Types of Fractions (Improper & Mixed
Numbers)
