NUR 108 – Dosage Calculations | Nursing Dosage Calculation Study Guide Medication Math, Safe Drug Administration, Practice Problems, and Comprehensive Review Questions with Detailed Rationales | Latest 2025–2026 Update

NUR 108 – Dosage Calculations | Nursing Dosage
Calculation Study Guide Medication Math, Safe Drug
Administration, Practice Problems, and
Comprehensive Review Questions with Detailed
Rationales | Latest 2025–2026 Update

Question 1
Convert 2,500 milligrams to grams.
A. 0.25 g
B. 2.5 g
C. 25 g
D. 250 g
Answer: B. 2.5 g
Rationale: 1 gram = 1,000 milligrams. Therefore, 2,500 mg ÷ 1,000 = 2.5 g. When
converting from smaller to larger units, divide.


Question 2
Convert 0.75 grams to milligrams.
A. 7.5 mg
B. 75 mg
C. 750 mg
D. 7,500 mg
Answer: C. 750 mg
Rationale: 1 gram = 1,000 milligrams. Therefore, 0.75 g × 1,000 = 750 mg. When
converting from larger to smaller units, multiply.


Question 3
Convert 4.2 liters to milliliters.

,A. 42 mL
B. 420 mL
C. 4,200 mL
D. 42,000 mL
Answer: C. 4,200 mL
Rationale: 1 liter = 1,000 milliliters. Therefore, 4.2 L × 1,000 = 4,200 mL.


Question 4
Convert 150 pounds to kilograms. (Round to the nearest tenth)
A. 68.0 kg
B. 68.2 kg
C. 68.5 kg
D. 70.0 kg
Answer: B. 68.2 kg
Rationale: 1 kg = 2.2 lb. Therefore, 150 lb ÷ 2.2 = 68.18 → 68.2 kg. Rounding to
the nearest tenth gives 68.2 kg.


Question 5
Convert 75 kilograms to pounds.
A. 150 lb
B. 165 lb
C. 175 lb
D. 185 lb
Answer: B. 165 lb
Rationale: 1 kg = 2.2 lb. Therefore, 75 kg × 2.2 = 165 lb.


Question 6
Convert 0.05 grams to milligrams.
A. 0.5 mg
B. 50 mg

,C. 500 mg
D. 5,000 mg
Answer: B. 50 mg
Rationale: 1 gram = 1,000 milligrams. Therefore, 0.05 g × 1,000 = 50 mg.


Question 7
Convert 500 micrograms to milligrams.
A. 0.05 mg
B. 0.5 mg
C. 5 mg
D. 50 mg
Answer: B. 0.5 mg
Rationale: 1 mg = 1,000 micrograms. Therefore, 500 mcg ÷ 1,000 = 0.5 mg.


Question 8
How many milliliters are in 1 tablespoon?
A. 5 mL
B. 15 mL
C. 30 mL
D. 45 mL
Answer: B. 15 mL
Rationale: 1 tablespoon (tbsp) = 15 mL. 1 teaspoon (tsp) = 5 mL. 1 ounce (oz) =
30 mL.


Question 9
How many milliliters are in 4 ounces?
A. 60 mL
B. 120 mL
C. 180 mL
D. 240 mL

, Answer: B. 120 mL
Rationale: 1 ounce = 30 mL. Therefore, 4 oz × 30 = 120 mL.


Question 10
Convert 0.125 mg to micrograms.
A. 1.25 mcg
B. 125 mcg
C. 1,250 mcg
D. 12,500 mcg
Answer: B. 125 mcg
Rationale: 1 mg = 1,000 mcg. Therefore, 0.125 mg × 1,000 = 125 mcg.


Question 11
Convert 8,500 mL to liters.
A. 0.85 L
B. 8.5 L
C. 85 L
D. 850 L
Answer: B. 8.5 L
Rationale: 1 L = 1,000 mL. Therefore, 8,500 mL ÷ 1,000 = 8.5 L.


Question 12
How many teaspoons are in 30 mL?
A. 2 tsp
B. 6 tsp
C. 8 tsp
D. 10 tsp
Answer: B. 6 tsp
Rationale: 1 teaspoon = 5 mL. Therefore, 30 mL ÷ 5 = 6 tsp.