Skip to content

Med math · 5 free problems

Insulin and heparin practice: units, units/mL, and units per hour

Units behave like any other amount. Find the units in each mL, then divide the ordered units by that number. Insulin is measured on an insulin syringe in practice; the exercises here practice the arithmetic.

Fictional labels. Round as each question says. How to round

A rationale sheet sits beside highlighted source material in a spiral notebookLECTURE 03My nursingnotesONE TOPIC AT A TIMETHE WHY BEHIND ITRationale

Insulin and heparin: work through the set

Question 1 of 5

Units per hour to mL per hour

In an infusion-math exercise, a practice bag is labeled 25,000 units in 250 mL. The exercise specifies 1,200 units/hour. What pump rate in mL/hour delivers that amount? Give the exact answer; no rounding is needed. Use only the supplied exercise values; this is arithmetic practice, not a dosing recommendation.

Worked solution and answer

Answer: 12 mL/hour.

Concentration: 25,000 units ÷ 250 mL = 100 units/mL. Rate: (1,200 units/hour) × (1 mL / 100 units) = 12 mL/hour.

Check: 12 mL/hour × 100 units/mL = 1,200 units/hour.

If you got 120: You divided by 10 instead of 100. Work out units per mL first, then divide the hourly units by it.

Question 2 of 5

A different bag concentration

In an infusion-math exercise, a practice bag is labeled 20,000 units in 500 mL. The exercise specifies 800 units/hour. What pump rate in mL/hour delivers that amount? Give the exact answer; no rounding is needed. Use only the supplied exercise values.

Worked solution and answer

Answer: 20 mL/hour.

Concentration: 20,000 units ÷ 500 mL = 40 units/mL. Rate: (800 units/hour) × (1 mL / 40 units) = 20 mL/hour.

Check: 20 mL/hour × 40 units/mL = 800 units/hour.

If you got 32,000: You multiplied by the concentration. Each mL already carries 40 units, so divide.

Question 3 of 5

A weight-based bolus in units

A fictional weight-based exercise specifies 80 units/kg for a weight of 70 kg. How many units does the exercise specify? Give the exact answer in units; no rounding is needed. Use only the supplied exercise values; this is not a dosing recommendation.

Worked solution and answer

Answer: 5,600 units.

70 kg × (80 units / kg) = 5,600 units. The kg units cancel.

Check: 5,600 units ÷ 70 kg = 80 units/kg.

If you got 0.875: You divided 70 by 80. Multiply the weight by the units per kilogram.

Question 4 of 5

Volume from a units-per-mL vial

A fictional practice vial is labeled 5,000 units/mL. The exercise requests 3,500 units. What volume contains 3,500 units? Give the exact answer in mL; write a zero before the decimal point.

Worked solution and answer

Answer: 0.7 mL.

3,500 units × (1 mL / 5,000 units) = 0.7 mL. The units cancel.

Check: 0.7 mL × 5,000 units/mL = 3,500 units.

If you got 1.43: You divided 5,000 by 3,500. The requested amount goes in the numerator.

Question 5 of 5

U-100 insulin as a volume

A fictional practice vial is labeled U-100, meaning 100 units/mL. The exercise requests 24 units. For the calculation, what volume in mL contains 24 units? Give the exact answer; write a zero before the decimal point. Insulin is normally measured in units on an insulin syringe; this exercise practices the concentration math only.

Worked solution and answer

Answer: 0.24 mL.

24 units × (1 mL / 100 units) = 0.24 mL.

Check: 0.24 mL × 100 units/mL = 24 units.

If you got 2.4: You divided by 10. U-100 means 100 units in each mL.

Keep practicing pharmacology

Create a free account or sign in to choose a pharmacology session, including medication administration and safety. This is broader practice; the session is not a dedicated dosage-calculation set.

Choose pharmacology practice

Your answers here stay in this browser when you sign up and return. They are not saved to your account.

Keep Going
All med math categoriesPractice pharmacology questionsTurn your pharmacology notes into practiceReview the lab values to know