Numeracy & Drug Calculations
7 free practice questions with explanations
PassNova has 7 free NMC CBT (Overseas Nurses) practice questions on Numeracy & Drug Calculations, each with a clear explanation. Practise them in the browser with instant feedback — 100% free, no sign-up, on any device. Updated for 2026.
Numeracy & Drug Calculations: example questions & answers
7 worked examples with answers and explanations below. Practise them in the browser with instant feedback on every answer.
A patient is prescribed paracetamol 1 g orally. The available tablets are 500 mg each. How many tablets should the nurse administer?
- A1 tablet
- B2 tablets✓
- C3 tablets
- D4 tablets
Answer: 1 g equals 1000 mg, and 1000 mg divided by 500 mg per tablet equals 2 tablets. This is a standard adult paracetamol dose.
A patient requires 500 mL of 0.9% sodium chloride to be infused over 4 hours via a gravity giving set delivering 20 drops per mL. What is the infusion rate in drops per minute (rounded to the nearest whole number)?
- A28 drops/min
- B42 drops/min✓
- C50 drops/min
- D63 drops/min
Answer: Volume 500 mL multiplied by 20 drops/mL equals 10000 drops, divided by 240 minutes equals approximately 42 drops per minute. This is the correct gravity infusion rate.
A child weighing 20 kg is prescribed a medicine at 5 mg/kg as a single dose. What total dose should be given?
- A25 mg
- B50 mg
- C100 mg✓
- D200 mg
Answer: 5 mg/kg multiplied by 20 kg equals 100 mg. Weight-based dosing requires multiplying the per-kilogram dose by the patient's weight.
A patient is prescribed 1.2 g of an antibiotic. The stock vial contains 600 mg in 5 mL once reconstituted. What volume should be drawn up?
- A5 mL
- B8 mL
- C10 mL✓
- D12 mL
Answer: 1.2 g equals 1200 mg, and using dose divided by stock multiplied by volume gives (1200/600) multiplied by 5 mL equals 10 mL. This is the correct volume to administer.
A 1000 mL bag of fluid is to run over 8 hours using a volumetric pump. What rate in mL/hour should the pump be set to?
- A100 mL/hour
- B125 mL/hour✓
- C150 mL/hour
- D175 mL/hour
Answer: 1000 mL divided by 8 hours equals 125 mL per hour. Volumetric pumps are programmed directly in millilitres per hour.
A patient is prescribed 75 mg of a drug available as 25 mg/mL oral solution. What volume should the nurse measure?
- A1 mL
- B2 mL
- C3 mL✓
- D4 mL
Answer: 75 mg divided by 25 mg/mL equals 3 mL. Dividing the prescribed dose by the concentration gives the required volume.
Insulin 12 units is prescribed. Using a U-100 insulin syringe, to which marking should the nurse draw up?
- A1.2 mL
- B0.12 mL
- C12 units on the insulin syringe scale✓
- D120 units
Answer: Insulin must always be measured using an insulin syringe calibrated in units, drawing up to the 12-unit mark. Using a standard millilitre syringe for insulin is unsafe and never acceptable.