Educational arithmetic only. All quantities below are invented CARE teaching examples, not patient orders, safe-dose ranges or administration instructions. Correct arithmetic does not establish clinical appropriateness. Use actual orders, product labeling, device limits and organizational policy in practice.
One mixed worksheet, with room to show your setup
Use these eight original exercises to practice choosing units before calculating. All concentrations, tablet amounts and volume/time combinations are invented. They are not copied exam questions, clinical orders or recommendations for a patient.
This is an ungraded printable learning worksheet. Its worked solutions are deliberately public and included below. It does not collect answers, generate a score or unlock paid material. Existing skill practice remains the place for server-graded exercises.
- Use your browser’s Print command to print or save this page as a PDF. Review the print preview and paper size first.
- The solutions begin on a separate printed page. Print only the exercise pages first if you want to work without seeing them.
- For each task, write the requested unit, factor setup, cancellation, unrounded result and final labeled answer.
- Compare the reasoning after you finish. Keep the first incorrect step in an error log; an arithmetic slip and a setup error need different practice.
If you cannot choose the factor orientation, start with the dimensional-analysis lesson. You do not need to memorize a new formula for each row.
Worksheet instructions
Use 1 g = 1,000 mg, 1 L = 1,000 mL and 1 hour = 60 minutes. Each exercise supplies its other assumptions. Keep intermediate precision. Unless the task explicitly asks for rounding, give its exact result. Never infer that these classroom rounding instructions apply to an actual medication or device.
Use a leading zero for values below one. Include units in every final answer. Nothing in this worksheet asks you to decide whether a patient should receive a dose or whether a medication can be divided.
Method and notation reference: Open RN Nursing Skills, chapter 5. Exact metric prefixes: NIST. The fictional problems and solutions are CARE-created, not reproduced from those references.
Name/date (optional, on your printed copy): __________________________
W3-01 — Metric mass
Convert 0.48 g to mg. Give the exact result.
W3-02 — Metric volume
Convert 750 mL to L. Give the exact result.
W3-03 — Whole tablets
A fictional tablet contains 75 mg. How many whole tablets contain 225 mg? Give the exact count. No tablet splitting is involved.
W3-04 — Fictional liquid concentration
A fictional solution contains 80 mg in 4 mL. What volume contains 140 mg? Give the exact volume in mL.
W3-05 — Volume per hour
For this arithmetic exercise, 675 mL is distributed evenly over 4.5 hours. Find mL/hour. Give the exact rate.
W3-06 — Drops per minute
A fictional exercise gives 320 mL over 2 hours and a specified factor of 15 drops/mL. Find drops/minute. Round only the final result to the nearest whole drop/minute.
W3-07 — Time in hours and minutes
For this arithmetic exercise, find how long 525 mL lasts at a constant 150 mL/hour. Report exact hours, then hours and minutes.
W3-08 — Specified final rounding
A fictional solution contains 45 mg in 2 mL. Find the volume containing 80 mg. For this exercise only, round the final volume to the nearest tenth of a mL.
Separate worked solutions
Match the exercise ID before checking an answer. Different equivalent setups can be valid. The unit relationships and requested final quantity must still agree. These visible explanations are study material, not a hidden answer key to a graded test.
W3-01: 480 mg
0.48 g × (1,000 mg / 1 g) = 480 mg.
Independent check: 480 mg ÷ 1,000 mg/g = 0.48 g.
W3-02: 0.75 L
750 mL × (1 L / 1,000 mL) = 0.75 L.
Independent check: 0.75 L × 1,000 mL/L = 750 mL.
W3-03: 3 tablets
225 mg × (1 tablet / 75 mg) = 3 tablets.
Independent check: 3 tablets × 75 mg/tablet = 225 mg.
W3-04: 7 mL
140 mg × (4 mL / 80 mg) = 560/80 mL = 7 mL.
Independent check: 80/4 = 20 mg/mL; 7 mL × 20 mg/mL = 140 mg.
W3-05: 150 mL/hour
675 mL / 4.5 hours = 150 mL/hour.
Independent check: 150 mL/hour × 4.5 hours = 675 mL.
W3-06: 40 drops/minute
(320 mL / 2 hours) × (1 hour / 60 minutes) × (15 drops / 1 mL) = 4,800/120 drops/minute = 40 drops/minute.
Independent check: 40 drops/minute × 120 minutes ÷ 15 drops/mL = 320 mL. The factor is supplied, not assumed.
W3-07: 3.5 hours = 3 hours 30 minutes
525 mL × (1 hour / 150 mL) = 3.5 hours. The remaining 0.5 hour × 60 minutes/hour = 30 minutes.
Independent check: 3 hours 30 minutes = 3.5 hours; 3.5 × 150 = 525 mL. It is not 3 hours 50 minutes.
W3-08: 3.6 mL (exercise rounding rule)
80 mg × (2 mL / 45 mg) = 160/45 mL = 32/9 mL = 3.555… mL; to the nearest tenth, 3.6 mL.
Independent check: The unrounded fraction times 45/2 mg/mL returns 80 mg. The rounded 3.6 mL represents 81 mg: rounding changed the represented quantity. The exercise rule does not establish clinical acceptability.
Choose the next practice from the mistake
- For conversion direction errors, revisit metric conversions.
- For concentration denominator mistakes, try liquid-volume practice; keep the whole ratio together.
- For confusion between rate and duration, compare mL/hour practice with infusion-time practice.
- For rounding differences, compare unrounded quantities and the stated rule before changing your setup.
Finishing eight exercises does not establish clinical competency or predict an exam score. Use the work to identify a concrete skill to practice again, rather than treating completion as a readiness label.
Continue learning
- Dimensional analysis
- Existing graded dosage practice by skill
- Free NCLEX-RN practice and free NCLEX-PN practice
Original public instruction; no paid question-bank material is reproduced. These pages do not grade your work or predict an exam result.