ATI Dosage Calculation RN Fundamentals Proctored Assessment 3.2
Practice Assessment with Verified Answers & Rationales
Instructions: Solve each problem. Round your final answer according to standard
nursing rounding rules unless otherwise specified. Standard rounding rules: Round to
the nearest whole number when calculating tablets/capsules; round IV rates to the
nearest whole mL/hr; round gtt/min to the nearest whole number; round weight-based
doses to the nearest tenth unless otherwise indicated.
Q1: A provider orders phenytoin (Dilantin) 0.2 g PO now. The pharmacy sends
phenytoin 100 mg capsules. How many capsules should the nurse administer?
A. 0.5 capsules
B. 1 capsule
C. 2 capsules. [CORRECT]
D. 4 capsules
Correct Answer: C
Rationale: First, convert grams to milligrams to match the available supply: 0.2 g = 200
mg. Then use the formula: Desired ÷ Have = Amount to administer. 200 mg ÷ 100
mg/capsule = 2 capsules. The nurse should administer 2 capsules. Distractor A results
from dividing 100 by 200 (inverted formula). Distractor B results from failing to convert
grams to milligrams (thinking 0.2 = 100 mg). Distractor D results from multiplying
instead of dividing.
Q2: The provider orders furosemide (Lasix) 40 mg PO daily. Available: furosemide oral
solution 10 mg/1 mL. How many mL should the nurse administer?
A. 0.25 mL
B. 4 mL. [CORRECT]
C. 40 mL
D. 400 mL
,Correct Answer: B
Rationale: Use the formula: Desired ÷ Have × Volume = Amount. 40 mg ÷ 10 mg × 1 mL
= 4 mL. The nurse should administer 4 mL of the oral solution. Distractor A results from
inverting the calculation (10 ÷ 40). Distractor C results from failing to perform the
division and simply carrying over the desired dose. Distractor D results from a decimal
error (multiplying 40 × 10 instead of dividing).
Q3: A patient is to receive 1,000 mL of 0.9% sodium chloride IV over 8 hours. The IV
tubing has a drop factor of 15 gtt/mL. At how many gtt/min should the nurse set the
manual IV flow rate?
A. 31 gtt/min. [CORRECT]
B. 125 gtt/min
C. 19 gtt/min
D. 63 gtt/min
Correct Answer: A
Rationale: Use the formula: (Total volume × Drop factor) ÷ Total minutes = gtt/min. First,
convert 8 hours to minutes: 8 × 60 = 480 minutes. Then calculate: (1,000 mL × 15
gtt/mL) ÷ 480 min = 15,000 ÷ 480 = 31.25 gtt/min. Round to the nearest whole number:
31 gtt/min. Distractor B results from calculating mL/hr (1,000 ÷ 8 = 125) but failing to
convert to gtt/min. Distractor C results from using 60 gtt/mL (microdrip) instead of 15
gtt/mL. Distractor D results from a calculation error (using 240 minutes instead of 480).
Q4: The provider orders heparin 5,000 units subcutaneous daily. Available: heparin
10,000 units/mL. How many mL should the nurse administer?
A. 5 mL
B. 2 mL
C. 0.5 mL. [CORRECT]
, D. 0.2 mL
Correct Answer: C
Rationale: Use the formula: Desired ÷ Have × Volume = Amount. 5,000 units ÷ 10,000
units × 1 mL = 0.5 mL. The nurse should administer 0.5 mL. Distractor A results from
subtracting 10,000 - 5,000. Distractor B results from dividing 10,000 by 5,000. Distractor
D results from inverting the division (5,000/10,000 = 0.5, but misplacing decimal to get
0.2).
Q5: A child weighs 22 lb. The provider orders amoxicillin 20 mg/kg/day PO divided in 2
doses. How many mg should the nurse administer per dose?
A. 100 mg
B. 200 mg. [CORRECT]
C. 400 mg
D. 440 mg
Correct Answer: B
Rationale: First convert weight: 22 lb ÷ 2.2 lb/kg = 10 kg. Calculate daily dose: 20
mg/kg/day × 10 kg = 200 mg/day. Divide by 2 doses: 200 mg ÷ 2 = 100 mg per dose.
Wait—let me recalculate: 20 mg/kg/day × 10 kg = 200 mg/day total. Divided by 2 doses
= 100 mg per dose. However, reviewing the options, B (200 mg) would be the daily
amount, not per dose. Let me recheck: 22 lb = 10 kg. 20 mg/kg = 200 mg total daily
dose. Divided by 2 doses = 100 mg per dose. Since 100 mg is option A, but let me
verify: Actually, 22 lb ÷ 2.2 = 10 kg exactly. 10 kg × 20 mg/kg = 200 mg/day. 200 ÷ 2 =
100 mg per dose. The correct answer should be 100 mg (Option A).
Correction: Option A. 100 mg. [CORRECT]
Correct Answer: A
Practice Assessment with Verified Answers & Rationales
Instructions: Solve each problem. Round your final answer according to standard
nursing rounding rules unless otherwise specified. Standard rounding rules: Round to
the nearest whole number when calculating tablets/capsules; round IV rates to the
nearest whole mL/hr; round gtt/min to the nearest whole number; round weight-based
doses to the nearest tenth unless otherwise indicated.
Q1: A provider orders phenytoin (Dilantin) 0.2 g PO now. The pharmacy sends
phenytoin 100 mg capsules. How many capsules should the nurse administer?
A. 0.5 capsules
B. 1 capsule
C. 2 capsules. [CORRECT]
D. 4 capsules
Correct Answer: C
Rationale: First, convert grams to milligrams to match the available supply: 0.2 g = 200
mg. Then use the formula: Desired ÷ Have = Amount to administer. 200 mg ÷ 100
mg/capsule = 2 capsules. The nurse should administer 2 capsules. Distractor A results
from dividing 100 by 200 (inverted formula). Distractor B results from failing to convert
grams to milligrams (thinking 0.2 = 100 mg). Distractor D results from multiplying
instead of dividing.
Q2: The provider orders furosemide (Lasix) 40 mg PO daily. Available: furosemide oral
solution 10 mg/1 mL. How many mL should the nurse administer?
A. 0.25 mL
B. 4 mL. [CORRECT]
C. 40 mL
D. 400 mL
,Correct Answer: B
Rationale: Use the formula: Desired ÷ Have × Volume = Amount. 40 mg ÷ 10 mg × 1 mL
= 4 mL. The nurse should administer 4 mL of the oral solution. Distractor A results from
inverting the calculation (10 ÷ 40). Distractor C results from failing to perform the
division and simply carrying over the desired dose. Distractor D results from a decimal
error (multiplying 40 × 10 instead of dividing).
Q3: A patient is to receive 1,000 mL of 0.9% sodium chloride IV over 8 hours. The IV
tubing has a drop factor of 15 gtt/mL. At how many gtt/min should the nurse set the
manual IV flow rate?
A. 31 gtt/min. [CORRECT]
B. 125 gtt/min
C. 19 gtt/min
D. 63 gtt/min
Correct Answer: A
Rationale: Use the formula: (Total volume × Drop factor) ÷ Total minutes = gtt/min. First,
convert 8 hours to minutes: 8 × 60 = 480 minutes. Then calculate: (1,000 mL × 15
gtt/mL) ÷ 480 min = 15,000 ÷ 480 = 31.25 gtt/min. Round to the nearest whole number:
31 gtt/min. Distractor B results from calculating mL/hr (1,000 ÷ 8 = 125) but failing to
convert to gtt/min. Distractor C results from using 60 gtt/mL (microdrip) instead of 15
gtt/mL. Distractor D results from a calculation error (using 240 minutes instead of 480).
Q4: The provider orders heparin 5,000 units subcutaneous daily. Available: heparin
10,000 units/mL. How many mL should the nurse administer?
A. 5 mL
B. 2 mL
C. 0.5 mL. [CORRECT]
, D. 0.2 mL
Correct Answer: C
Rationale: Use the formula: Desired ÷ Have × Volume = Amount. 5,000 units ÷ 10,000
units × 1 mL = 0.5 mL. The nurse should administer 0.5 mL. Distractor A results from
subtracting 10,000 - 5,000. Distractor B results from dividing 10,000 by 5,000. Distractor
D results from inverting the division (5,000/10,000 = 0.5, but misplacing decimal to get
0.2).
Q5: A child weighs 22 lb. The provider orders amoxicillin 20 mg/kg/day PO divided in 2
doses. How many mg should the nurse administer per dose?
A. 100 mg
B. 200 mg. [CORRECT]
C. 400 mg
D. 440 mg
Correct Answer: B
Rationale: First convert weight: 22 lb ÷ 2.2 lb/kg = 10 kg. Calculate daily dose: 20
mg/kg/day × 10 kg = 200 mg/day. Divide by 2 doses: 200 mg ÷ 2 = 100 mg per dose.
Wait—let me recalculate: 20 mg/kg/day × 10 kg = 200 mg/day total. Divided by 2 doses
= 100 mg per dose. However, reviewing the options, B (200 mg) would be the daily
amount, not per dose. Let me recheck: 22 lb = 10 kg. 20 mg/kg = 200 mg total daily
dose. Divided by 2 doses = 100 mg per dose. Since 100 mg is option A, but let me
verify: Actually, 22 lb ÷ 2.2 = 10 kg exactly. 10 kg × 20 mg/kg = 200 mg/day. 200 ÷ 2 =
100 mg per dose. The correct answer should be 100 mg (Option A).
Correction: Option A. 100 mg. [CORRECT]
Correct Answer: A
