Conversions & Abbreviations — practice set (Q1–40)

Check yourself

40 review questions from the chapter. Try each one, then open the answer.

1. Question 1. Scenario: A nurse is reconciling a patient's home medication list and must record the total daily intake in grams for the chart. Order: Record 2500 mg of the medication. Available: N/A — metric conversion only. Question: Convert 2500 mg to grams. Report the exact value.

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   Correct answer: 2.5 g Setup (dimensional analysis): 2500 mg × (1 g / 1000 mg) Raw calculation: 2500 / 1000 = 2.5 Rounding: Exact conversion — no rounding needed. Final answer: 2.5 g Rationale: There are 1000 mg in 1 g, so dividing milligrams by 1000 converts to grams. Clinical pearl: Move the decimal three places to the LEFT to convert mg → g (2500. mg → 2.5 g).

2. Question 2. Scenario: A provider asks a nurse to prepare a weight-based dose that is ordered in grams but must be measured on a milligram scale. Order: Prepare 0.75 g of the medication. Available: N/A — metric conversion only. Question: How many milligrams is 0.75 g? Report the exact value.

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   Correct answer: 750 mg Setup (dimensional analysis): 0.75 g × (1000 mg / 1 g) Raw calculation: 0.75 × 1000 = 750 Rounding: Exact conversion — no rounding needed. Final answer: 750 mg Rationale: There are 1000 mg in 1 g, so multiplying grams by 1000 converts to milligrams. Clinical pearl: Move the decimal three places to the RIGHT to convert g → mg (0.75 g → 750 mg).

3. Question 3. Scenario: A nurse is transcribing a microgram dose onto a medication administration record that lists the dose in milligrams. Order: Record 1500 mcg of the medication. Available: N/A — metric conversion only. Question: How many milligrams is 1500 mcg? Report the exact value.

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   Correct answer: 1.5 mg Setup (dimensional analysis): 1500 mcg × (1 mg / 1000 mcg) Raw calculation: 1500 / 1000 = 1.5 Rounding: Exact conversion — no rounding needed. Final answer: 1.5 mg Rationale: There are 1000 mcg in 1 mg, so dividing micrograms by 1000 converts to milligrams. Clinical pearl: mcg and mg differ by a factor of 1000; a misplaced decimal is a 1000-fold error.

4. Question 4. Scenario: A nurse must dilute a small parenteral dose that is ordered in milligrams but prepared from a microgram concentration. Order: Prepare 0.4 mg of the medication. Available: N/A — metric conversion only. Question: How many micrograms is 0.4 mg? Report the exact value.

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   Correct answer: 400 mcg Setup (dimensional analysis): 0.4 mg × (1000 mcg / 1 mg) Raw calculation: 0.4 × 1000 = 400 Rounding: Exact conversion — no rounding needed. Final answer: 400 mcg Rationale: There are 1000 mcg in 1 mg, so multiplying milligrams by 1000 converts to micrograms. Clinical pearl: Always carry the unit through the conversion so mg cancels and mcg remains.

5. Question 5. Scenario: A nurse is verifying an IV fluid order written in liters against a pump that is programmed in milliliters. Order: Infuse 1.5 L of lactated Ringer's solution. Available: N/A — metric conversion only. Question: How many milliliters is 1.5 L? Report the exact value.

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   Correct answer: 1500 mL Setup (dimensional analysis): 1.5 L × (1000 mL / 1 L) Raw calculation: 1.5 × 1000 = 1500 Rounding: Exact conversion — no rounding needed. Final answer: 1500 mL Rationale: There are 1000 mL in 1 L, so multiplying liters by 1000 converts to milliliters. Clinical pearl: IV pumps are programmed in mL/hr; converting L → mL first prevents a 1000-fold programming error.

6. Question 6. Scenario: A nurse documents a patient's oral fluid intake in liters, but the graduate measured the intake in milliliters. Order: Record a measured intake of 250 mL. Available: N/A — metric conversion only. Question: How many liters is 250 mL? Report the exact value.

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   Correct answer: 0.25 L Setup (dimensional analysis): 250 mL × (1 L / 1000 mL) Raw calculation: 250 / 1000 = 0.25 Rounding: Exact conversion — no rounding needed. Final answer: 0.25 L Rationale: There are 1000 mL in 1 L, so dividing milliliters by 1000 converts to liters. Clinical pearl: Intake and output are often charted in mL even when the order is written in liters — convert consistently.

7. Question 7. Scenario: A parent calls the clinic asking how much liquid medicine to give using a milliliter dosing cup because the household teaspoon is missing. Order: Give 3 teaspoons of the medication. Available: Household teaspoon (1 tsp = 5 mL). Question: How many milliliters equals 3 teaspoons? Report the exact value.

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   Correct answer: 15 mL Setup (dimensional analysis): 3 tsp × (5 mL / 1 tsp) Raw calculation: 3 × 5 = 15 Rounding: Exact conversion — no rounding needed. Final answer: 15 mL Rationale: One household teaspoon is exactly 5 mL (1 tsp = 5 mL), so 3 teaspoons equal 15 mL. Clinical pearl: Teach caregivers to use a marked dosing cup or syringe rather than a kitchen spoon, which is inaccurate.

8. Question 8. Scenario: A nurse is teaching a caregiver to measure a dose using a medicine cup when the order is written in tablespoons. Order: Give 2 tablespoons of the medication. Available: Household tablespoon (1 tbsp = 15 mL). Question: How many milliliters equals 2 tablespoons? Report the exact value.

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   Correct answer: 30 mL Setup (dimensional analysis): 2 tbsp × (15 mL / 1 tbsp) Raw calculation: 2 × 15 = 30 Rounding: Exact conversion — no rounding needed. Final answer: 30 mL Rationale: One household tablespoon is exactly 15 mL (1 tbsp = 15 mL), so 2 tablespoons equal 30 mL. Clinical pearl: One tablespoon equals three teaspoons (15 mL = 3 × 5 mL); a "table" spoonful from the kitchen is not a reliable 15 mL.

9. Question 9. Scenario: A nurse calculates the fluid a patient will receive with a meal when the order is written in fluid ounces but the intake sheet records milliliters. Order: Give 4 fluid ounces of juice with the meal. Available: Household fluid ounce (1 fl oz ≈ 30 mL, conventionally rounded). Question: Approximately how many milliliters equals 4 fluid ounces? Report the exact value using the conventional approximation.

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   Correct answer: 120 mL Setup (dimensional analysis): 4 fl oz × (30 mL / 1 fl oz) [conventional: 1 fl oz ≈ 30 mL] Raw calculation: 4 × 30 = 120 Rounding: Conventional approximation — the ≈ value is used as stated. Final answer: ≈120 mL Rationale: For nursing purposes, 1 fluid ounce is conventionally rounded to 30 mL, so 4 ounces are approximately 120 mL. (The exact value, 1 fl oz = 29.57 mL, would give 118.3 mL.) Clinical pearl: The 30 mL/oz approximation is accurate enough for oral fluid tracking; note the "≈" rather than "=".

10. Question 10. Scenario: A nurse needs the patient's weight in kilograms to verify a weight-based medication order, but the scale reads in pounds. Order: Obtain the patient's weight in kilograms for a medication that is dosed per kilogram. Available: Patient weight = 154 lb (1 kg ≈ 2.2 lb, conventionally rounded). Question: Convert 154 lb to kilograms and round to the nearest tenth of a kilogram.

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    Correct answer: 70 kg Setup (dimensional analysis): 154 lb × (1 kg / 2.2 lb) [conventional: 1 kg ≈ 2.2 lb] Raw calculation: 154 / 2.2 = 70.0 Rounding: The question specifies rounding to the nearest tenth of a kilogram; 70.0 kg. Final answer: 70 kg Rationale: Dividing pounds by 2.2 converts to kilograms; 154 / 2.2 = 70 kg exactly. Clinical pearl: Always reweigh or verify a stated weight before a weight-based dose — a wrong weight is a wrong dose.

11. Question 11. Scenario: A nurse is teaching a family member in the United States the patient's weight, which is documented in kilograms. Order: State the patient's weight in pounds for home monitoring. Available: Patient weight = 45 kg (1 kg ≈ 2.2 lb, conventionally rounded). Question: Approximately how many pounds is 45 kg? Report the exact value using the conventional approximation.

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    Correct answer: 99 lb Setup (dimensional analysis): 45 kg × (2.2 lb / 1 kg) [conventional: 1 kg ≈ 2.2 lb] Raw calculation: 45 × 2.2 = 99 Rounding: Conventional approximation — the ≈ value is used as stated. Final answer: ≈99 lb Rationale: Multiplying kilograms by 2.2 converts to pounds; 45 kg ≈ 99 lb. Clinical pearl: kg → lb multiply by 2.2; lb → kg divide by 2.2. Keep the direction straight to avoid a 2.2-fold error.

12. Question 12. Scenario: A provider orders an antibiotic for a patient with a respiratory infection, but the order is written in grams while the pharmacy dispenses milligram tablets. Order: Amoxicillin 0.5 g PO. Available: Amoxicillin 250 mg tablets. Question: How many tablets should the nurse administer per dose? A. 0.5 tablet B. 1 tablet C. 2 tablets D. 4 tablets

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    Correct answer: C. 2 tablets Setup (dimensional analysis): 0.5 g × (1000 mg / 1 g) × (1 tab / 250 mg) Raw calculation: 0.5 × 1000 = 500 mg; 500 / 250 = 2 Rounding: Tablets — a whole number; no rounding needed. Final answer: 2 tablets Rationale: Convert the gram order to milligrams first (0.5 g = 500 mg), then divide by the tablet strength (500 mg / 250 mg per tablet = 2 tablets). Clinical pearl: Never mix units — convert the order and the available strength to the SAME unit before dividing.

13. Question 13. Scenario: A nurse prepares a thyroid hormone replacement for an older adult. The order and the tablet strength are expressed in different metric units. Order: Levothyroxine 0.075 mg PO daily. Available: Levothyroxine 75 mcg tablets. Question: How many tablets should the nurse administer?

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    Correct answer: 1 tablet Setup (dimensional analysis): 0.075 mg × (1000 mcg / 1 mg) × (1 tab / 75 mcg) Raw calculation: 0.075 × 1000 = 75 mcg; 75 / 75 = 1 Rounding: Tablets — a whole number; no rounding needed. Final answer: 1 tablet Rationale: 0.075 mg is exactly 75 mcg, and the tablet strength is 75 mcg, so one tablet delivers the ordered dose. Clinical pearl: Levothyroxine strengths are commonly expressed in mcg; convert mg → mcg before selecting the tablet.

14. Question 14. Scenario: A nurse is restocking IV fluids for a patient whose 24-hour order is written in liters, but the supply room stocks 500 mL bags. Order: Normal saline 2 L IV over 24 hours. Available: Normal saline 500 mL bags. Question: How many 500 mL bags are needed to supply 2 L in a 24-hour period?

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    Correct answer: 4 bags Setup (dimensional analysis): 2 L × (1000 mL / 1 L) × (1 bag / 500 mL) Raw calculation: 2 × 1000 = 2000 mL; 2000 / 500 = 4 Rounding: Whole number of bags — no rounding needed. Final answer: 4 bags Rationale: 2 L = 2000 mL; each bag holds 500 mL, so 2000 / 500 = 4 bags. Clinical pearl: When counting containers, always round UP to the next whole bag only if a fraction of a bag would be required — here it divides evenly.

15. Question 15. Scenario: A caregiver must give a dose measured with a household teaspoon, but the order is written in tablespoons. Order: Give 1 tablespoon of the medication. Available: Household teaspoon (1 tsp = 5 mL); household tablespoon (1 tbsp = 15 mL). Question: How many teaspoons equal 1 tablespoon? Report the exact value.

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    Correct answer: 3 teaspoons Setup (dimensional analysis): 1 tbsp × (15 mL / 1 tbsp) × (1 tsp / 5 mL) Raw calculation: 15 / 5 = 3 Rounding: Exact conversion — no rounding needed. Final answer: 3 teaspoons Rationale: One tablespoon is 15 mL and one teaspoon is 5 mL, so 15 / 5 = 3 teaspoons per tablespoon. Clinical pearl: 1 tbsp = 3 tsp = 15 mL — a useful household conversion to remember.

16. Question 16. Scenario: A nurse prepares a patient's prescribed fluid allowance using a graduated cylinder calibrated in milliliters, but the order is written in ounces. Order: Give 6 fluid ounces of oral fluid. Available: Household fluid ounce (1 fl oz ≈ 30 mL, conventionally rounded). Question: Approximately how many milliliters equals 6 fluid ounces? Report the exact value using the conventional approximation.

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    Correct answer: 180 mL Setup (dimensional analysis): 6 fl oz × (30 mL / 1 fl oz) [conventional: 1 fl oz ≈ 30 mL] Raw calculation: 6 × 30 = 180 Rounding: Conventional approximation — the ≈ value is used as stated. Final answer: ≈180 mL Rationale: Using the nursing convention of 1 fl oz ≈ 30 mL, 6 ounces are approximately 180 mL. Clinical pearl: Track all oral fluid in mL; ounces must be converted so intake totals are consistent.

17. Question 17. Scenario: A provider orders a weight-based antipyretic for a febrile toddler. The nurse must first convert the weight to kilograms. Order: Ibuprofen 10 mg/kg PO now. Available: Patient weight = 66 lb (1 kg ≈ 2.2 lb, conventionally rounded). Ibuprofen 100 mg/5 mL oral suspension. Question: Calculate the single dose in milligrams. Round to the nearest whole milligram.

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    Correct answer: 300 mg Setup (dimensional analysis): 66 lb × (1 kg / 2.2 lb) = 30 kg; 30 kg × (10 mg / 1 kg) Raw calculation: 66 / 2.2 = 30 kg; 30 × 10 = 300 Rounding: Whole milligrams — 300 mg (no fractional remainder). Final answer: 300 mg Rationale: Convert pounds to kilograms (66 / 2.2 = 30 kg), then multiply by the ordered 10 mg/kg (30 × 10 = 300 mg). Clinical pearl: Ibuprofen 10 mg/kg/dose is a commonly taught pediatric reference; confirm the weight before calculating.

18. Question 18. Scenario: A nursing student is interpreting a new medication order and must identify the correct meaning of a route abbreviation before administration. Order: "Give 500 mg of the medication PO." Question: What does the abbreviation "PO" mean? A. Post-operatively B. By mouth C. Per ounce D. After meals

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    Correct answer: B. By mouth Setup (dimensional analysis): N/A — abbreviation interpretation. Raw calculation: N/A Rounding: N/A Final answer: By mouth Rationale: "PO" is the Latin abbreviation per os, meaning "by mouth." Clinical pearl: Route abbreviations are a common source of error — when in doubt, write the route out in full.

19. Question 19. Scenario: A nurse must document a patient's total daily intake of a medication that is ordered twice daily. Order: Cephalexin 250 mg BID. Available: N/A — frequency calculation only. Question: What total daily dose (in milligrams) will the patient receive?

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    Correct answer: 500 mg/day Setup (dimensional analysis): 250 mg/dose × 2 doses/day Raw calculation: 250 × 2 = 500 Rounding: Whole milligrams — no rounding needed. Final answer: 500 mg/day Rationale: "BID" means twice daily, so the 250 mg dose is given two times in 24 hours: 250 × 2 = 500 mg/day. Clinical pearl: Total daily dose = single dose × number of doses per day; check this before flagging an order as too high or too low.

20. Question 20. Scenario: A nurse is reviewing a pain-management order and must understand when the medication should be given. Order: "Morphine 2 mg IV q4h PRN for pain." Question: What does the abbreviation "PRN" mean? A. As needed B. Every night C. After meals D. When awake

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    Correct answer: A. As needed Setup (dimensional analysis): N/A — abbreviation interpretation. Raw calculation: N/A Rounding: N/A Final answer: As needed Rationale: "PRN" is the Latin abbreviation pro re nata, meaning "as needed" or "as the situation requires." Clinical pearl: A PRN order must include the reason (e.g., "for pain") and a minimum interval (e.g., "q4h") to be safely administered.

21. Question 21. Scenario: A new graduate is labeling four syringes for different parenteral routes and must match each abbreviation to the correct tissue layer or site. Question: Which abbreviation indicates a medication given into the dermis (just beneath the epidermis)? A. IV B. IM C. SubQ D. ID

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    Correct answer: D. ID Setup (dimensional analysis): N/A — abbreviation interpretation. Raw calculation: N/A Rounding: N/A Final answer: ID (intradermal) Rationale: ID = intradermal (into the dermis, just beneath the epidermis). IV = intravenous, IM = intramuscular, SubQ = subcutaneous. Clinical pearl: The angle of insertion matches the depth of the target layer: ID ~5–15°, SubQ ~45°, IM ~90°.

22. Question 22. Scenario: A nurse is auditing medication orders for compliance with The Joint Commission "Do Not Use" list and finds one order with a decimal error. Question: Which of the following orders contains a trailing zero error? A. 2 mg B. 2.0 mg C. 0.2 mg D. 20 mg

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    Correct answer: B. 2.0 mg Setup (dimensional analysis): N/A — order-error identification. Raw calculation: N/A Rounding: N/A Final answer: 2.0 mg contains a trailing zero Rationale: A trailing zero after a decimal point ("2.0") can be misread as "20" if the decimal is missed, causing a 10-fold overdose. It should be written "2 mg." Clinical pearl: Joint Commission "Do Not Use": never write a zero after a decimal point (write 2 mg, not 2.0 mg).

23. Question 23. Scenario: A nurse reviews a handwritten order and notices a decimal point written without a preceding zero. Question: Which of the following orders is unsafe because it lacks a leading zero? A. 0.5 mg B. .5 mg C. 0.05 mg D. 5 mg

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    Correct answer: B. .5 mg Setup (dimensional analysis): N/A — order-error identification. Raw calculation: N/A Rounding: N/A Final answer: .5 mg lacks a leading zero Rationale: A decimal without a leading zero (".5") can be misread as "5," causing a 10-fold overdose. It should be written "0.5 mg." Clinical pearl: Joint Commission "Do Not Use": always place a zero before a decimal point (write 0.5 mg, not .5 mg).

24. Question 24. Scenario: A nurse notices that a medication order uses the abbreviation "U" for units and must rewrite it safely. Order: "Insulin regular 10 U subcutaneous." Question: What is the safest way to write this order? A. 10 U B. 10 u C. 10 units D. 10 IU

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    Correct answer: C. 10 units Setup (dimensional analysis): N/A — abbreviation rewriting. Raw calculation: N/A Rounding: N/A Final answer: 10 units Rationale: "U" can be mistaken for a zero ("10U" → "100") or the number four, causing a major overdose. The word "units" must be spelled out. Clinical pearl: "U" and "IU" are both on the Joint Commission "Do Not Use" list — write "units" or "international units" in full.

25. Question 25. Scenario: A nurse must transcribe an order that uses "IU" for international units onto a new medication administration record. Order: "Vitamin D 1000 IU PO daily." Question: What is the safest way to write this order? A. 1000 U B. 1000 international units C. 1000 iu D. 1000 units

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    Correct answer: B. 1000 international units Setup (dimensional analysis): N/A — abbreviation rewriting. Raw calculation: N/A Rounding: N/A Final answer: 1000 international units Rationale: "IU" can be misread as "IV" (intravenous) or "10," leading to a wrong route or wrong dose. Spell out "international units." Clinical pearl: "IU" is on the "Do Not Use" list — never substitute "U" or "units" for international units, because the two are not equivalent.

26. Question 26. Scenario: A nurse identifies the abbreviation "QD" in an order and must rewrite it to prevent a misread as "QID." Order: "Lisinopril 10 mg PO QD." Question: What is the safest way to write this order? A. QD B. q.d. C. daily D. Q.D.

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    Correct answer: C. daily Setup (dimensional analysis): N/A — abbreviation rewriting. Raw calculation: N/A Rounding: N/A Final answer: daily Rationale: "QD" can be misread as "QID" (four times daily) or "QOD" (every other day). Writing "daily" removes the ambiguity. Clinical pearl: "QD" is on the "Do Not Use" list; a misread can turn a once-daily drug into four-times-daily dosing.

27. Question 27. Scenario: A nurse finds the abbreviation "QOD" in an order and knows it is on the "Do Not Use" list. Order: "Medication X QOD." Question: How should this order be clarified and rewritten? A. Daily B. Every other day C. Four times daily D. At bedtime

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    Correct answer: B. Every other day Setup (dimensional analysis): N/A — abbreviation rewriting. Raw calculation: N/A Rounding: N/A Final answer: Every other day Rationale: "QOD" is easily confused with "QD" (daily) or "QID" (four times daily). It must be rewritten as "every other day." Clinical pearl: Because "QOD" and "QID" look alike, always spell out the frequency in full words.

28. Question 28. Scenario: A nurse receives a medication order that is missing essential elements and cannot be safely administered as written. Order: "Metoprolol 50 mg" — no route and no frequency are specified. Question: What should the nurse do before administering this medication?

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    Correct answer: Clarify the order before administering Setup (dimensional analysis): N/A — ambiguous/incomplete order. Raw calculation: N/A Rounding: N/A Final answer: Hold the medication and contact the provider to confirm the route and frequency Rationale: The order "Metoprolol 50 mg" is incomplete — it specifies neither route (PO vs IV) nor frequency (once daily, twice daily, etc.). Route and frequency change the dose, the formulation, and the timing, so the nurse cannot safely administer it as written. Clinical pearl: An order is not "safe" just because it has a number — it must include drug, dose, route, and frequency; clarify anything missing.

29. Question 29. Scenario: A provider orders a weight-based antibiotic for a child with otitis media, divided into two doses daily. The nurse must convert the weight and calculate each dose. Order: Amoxicillin 40 mg/kg/day PO divided q12h. Available: Patient weight = 33 lb (1 kg ≈ 2.2 lb, conventionally rounded). Question: Calculate the amount of amoxicillin per dose in milligrams. Round to the nearest whole milligram.

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    Correct answer: 300 mg per dose Setup (dimensional analysis): 33 lb × (1 kg / 2.2 lb) = 15 kg; 15 kg × (40 mg / 1 kg / day) = 600 mg/day; 600 mg/day ÷ 2 doses/day Raw calculation: 33 / 2.2 = 15 kg; 15 × 40 = 600 mg/day; 600 / 2 = 300 Rounding: Whole milligrams — 300 mg (no fractional remainder). Final answer: 300 mg per dose Rationale: Convert pounds to kilograms (33 / 2.2 = 15 kg), multiply by 40 mg/kg/day (15 × 40 = 600 mg/day), then divide by 2 doses (q12h) to get 300 mg per dose. Clinical pearl: For "mg/kg/day divided" orders, always calculate the DAILY total first, then divide by the number of doses.

30. Question 30. Scenario: A nurse must measure a liquid dose when the order is written in grams and the suspension is labeled in milligrams per milliliter. Order: Acetaminophen 1.5 g PO now. Available: Acetaminophen 250 mg/5 mL oral suspension. Question: How many milliliters should the nurse administer per dose? Round to the nearest whole milliliter.

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    Correct answer: 30 mL Setup (dimensional analysis): 1.5 g × (1000 mg / 1 g) × (5 mL / 250 mg) Raw calculation: 1.5 × 1000 = 1500 mg; 1500 × 5 / 250 = 30 Rounding: Whole milliliters — 30 mL (no fractional remainder). Final answer: 30 mL Rationale: Convert grams to milligrams (1.5 g = 1500 mg), then use the concentration (250 mg per 5 mL) to find the volume: 1500 mg × (5 mL / 250 mg) = 30 mL. Clinical pearl: 30 mL of a 250 mg/5 mL suspension is a large single volume — verify the order against the patient's maximum daily dose before giving.

31. Question 31. Scenario: A nurse must prepare a parenteral dose when the order is in milligrams and the vial concentration is in micrograms per milliliter. Order: Naloxone 0.5 mg IV now. Available: Naloxone 250 mcg/mL vial. Question: How many milliliters should the nurse draw up? Report the exact value.

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    Correct answer: 2 mL Setup (dimensional analysis): 0.5 mg × (1000 mcg / 1 mg) × (1 mL / 250 mcg) Raw calculation: 0.5 × 1000 = 500 mcg; 500 / 250 = 2 Rounding: Exact — no rounding needed. Final answer: 2 mL Rationale: Convert the milligram order to micrograms (0.5 mg = 500 mcg), then divide by the vial concentration (500 mcg / 250 mcg per mL = 2 mL). Clinical pearl: Parenteral doses are often ordered in mg but labeled in mcg/mL — always align units before drawing up.

32. Question 32. Scenario: A nurse is calculating a patient's total daily intake of a liquid medication ordered four times daily in tablespoons, but the intake record is in milliliters. Order: Milk of magnesia 1 tablespoon QID. Available: Household tablespoon (1 tbsp = 15 mL). Question: What is the total daily volume in milliliters? Report the exact value.

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    Correct answer: 60 mL/day Setup (dimensional analysis): 1 tbsp/dose × (15 mL / 1 tbsp) × 4 doses/day Raw calculation: 15 × 4 = 60 Rounding: Exact — no rounding needed. Final answer: 60 mL/day Rationale: One tablespoon = 15 mL, and "QID" means four times daily, so the total daily volume is 15 mL × 4 = 60 mL. Clinical pearl: Convert each household measure to mL FIRST, then multiply by the number of doses to get a correct daily total.

33. Question 33. Scenario: A nurse must teach a caregiver to measure a liquid dose with a household tablespoon because no dosing cup is available at home. Order: Cefdinir 750 mg PO once daily. Available: Cefdinir 125 mg/5 mL suspension. Household tablespoon (1 tbsp = 15 mL). Question: How many tablespoons should the caregiver measure per dose? Report the exact value.

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    Correct answer: 2 tablespoons Setup (dimensional analysis): 750 mg × (5 mL / 125 mg) × (1 tbsp / 15 mL) Raw calculation: 750 × 5 / 125 = 30 mL; 30 / 15 = 2 Rounding: Exact — no rounding needed. Final answer: 2 tablespoons Rationale: 750 mg at 125 mg/5 mL is 30 mL (750 × 5 / 125 = 30). Since 1 tablespoon = 15 mL, 30 mL = 2 tablespoons. Clinical pearl: When a dosing cup is unavailable, show the caregiver the exact household measure — but a marked syringe or cup is always preferred.

34. Question 34. Scenario: A nurse programs an IV pump for a patient who requires a total daily volume written in liters, to be delivered over a set number of hours. Order: Normal saline 1.5 L IV over 12 hours. Available: IV infusion pump calibrated in mL/hr. Question: What infusion rate in mL/hr should the nurse program? Round to the nearest whole number.

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    Correct answer: 125 mL/hr Setup (dimensional analysis): 1.5 L × (1000 mL / 1 L) ÷ 12 hr Raw calculation: 1.5 × 1000 = 1500 mL; 1500 / 12 = 125 Rounding: Whole mL/hr — 125 mL/hr (no fractional remainder). Final answer: 125 mL/hr Rationale: Convert liters to milliliters (1.5 L = 1500 mL), then divide by the infusion time (1500 / 12 = 125 mL/hr). Clinical pearl: mL/hr = total volume (mL) ÷ total time (hr); convert the volume unit to mL before dividing.

35. Question 35. Scenario: A nurse reviews a previous shift's administration and must determine how much medication (in milligrams) was actually delivered when a liquid volume was given. Available: Morphine oral solution 250 mg/5 mL. The prior nurse administered 10 mL. Question: How many milligrams of morphine were delivered in the 10 mL dose? Report the exact value.

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    Correct answer: 500 mg Setup (dimensional analysis): 10 mL × (250 mg / 5 mL) Raw calculation: 10 × 250 / 5 = 500 Rounding: Exact — no rounding needed. Final answer: 500 mg Rationale: The solution contains 250 mg per 5 mL, so 10 mL delivers 10 mL × (250 mg / 5 mL) = 500 mg. Clinical pearl: Reverse calculations (volume given → dose delivered) use the same dimensional-analysis setup, just solved for milligrams.

36. Question 36. Scenario: A nurse must administer a small volume that requires a precise measuring device. Order: Diphenhydramine 25 mg IM now. Available: Diphenhydramine 100 mg/mL vial. Question: What volume (in mL) should the nurse draw up, and which syringe provides the most accurate measurement? A. 0.25 mL, 1 mL tuberculin syringe B. 0.25 mL, 3 mL syringe C. 2.5 mL, 3 mL syringe D. 0.4 mL, 1 mL tuberculin syringe

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    Correct answer: A. 0.25 mL, 1 mL tuberculin syringe Setup (dimensional analysis): 25 mg × (1 mL / 100 mg) Raw calculation: 25 / 100 = 0.25 Rounding: Exact — 0.25 mL (no rounding needed). Final answer: 0.25 mL, 1 mL tuberculin syringe Rationale: 25 mg at 100 mg/mL is 0.25 mL. A 1 mL tuberculin syringe is calibrated in hundredths, allowing accurate measurement of 0.25 mL; a 3 mL syringe cannot measure this small volume precisely. Clinical pearl: Choose the smallest syringe that can hold the dose — small volumes (< 0.5 mL) need a 1 mL (tuberculin) syringe for accuracy.

37. Question 37. Scenario: A nurse instructs a caregiver to measure a liquid medication dose using a household teaspoon, but the order is written in fluid ounces. Order: Give 1 fluid ounce of the medication. Available: Household teaspoon (1 tsp = 5 mL); household fluid ounce (1 fl oz ≈ 30 mL, conventionally rounded). Question: How many teaspoons equal 1 fluid ounce (using the conventional approximation)? Report the exact value.

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    Correct answer: 6 teaspoons Setup (dimensional analysis): 1 fl oz × (30 mL / 1 fl oz) × (1 tsp / 5 mL) [conventional: 1 fl oz ≈ 30 mL] Raw calculation: 30 / 5 = 6 Rounding: Conventional approximation — the ≈ value is used as stated. Final answer: ≈6 teaspoons Rationale: 1 fluid ounce ≈ 30 mL, and 1 teaspoon = 5 mL, so 30 / 5 = 6 teaspoons per fluid ounce. Clinical pearl: 1 fl oz ≈ 30 mL ≈ 2 tbsp ≈ 6 tsp — a chain of household equivalents worth memorizing.

38. Question 38. Scenario: A nurse reviews a handwritten order for a cardiac medication and must both correct the decimal error and determine the number of tablets. Order: Digoxin .25 mg PO daily. Available: Digoxin 0.125 mg tablets. Question: (a) Identify and correct the decimal error in the order. (b) How many 0.125 mg tablets equal the corrected dose?

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    Correct answer: (a) 0.25 mg (add leading zero); (b) 2 tablets Setup (dimensional analysis): (b) 0.25 mg × (1 tab / 0.125 mg) Raw calculation: 0.25 / 0.125 = 2 Rounding: Tablets — a whole number; no rounding needed. Final answer: (a) "0.25 mg" (not ".25 mg"); (b) 2 tablets Rationale: ".25 mg" lacks a leading zero and could be misread as "25 mg" — a 100-fold overdose of a narrow-therapeutic-index drug. The safe form is "0.25 mg." Two 0.125 mg tablets equal 0.25 mg (0.25 / 0.125 = 2). Clinical pearl: With high-alert drugs like digoxin, always verify the decimal, the dose, and the tablet strength independently before administration.

39. Question 39. Scenario: A provider orders a weight-based dose of acetaminophen for a febrile infant. The nurse must verify the ordered dose against a well-known educational safe range. Order: Acetaminophen 300 mg PO q6h. Available: Patient weight = 22 lb (1 kg ≈ 2.2 lb, conventionally rounded). Well-known educational reference range: acetaminophen 10–15 mg/kg/dose (hypothetical for this question). Question: Using the reference range 10–15 mg/kg/dose, determine whether the ordered 300 mg dose is SAFE or UNSAFE. Show the converted weight, the safe-dose range, and the comparison.

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    Correct answer: UNSAFE — exceeds the maximum safe dose Converted weight: 22 lb × (1 kg / 2.2 lb) = 10 kg Minimum safe dose: 10 kg × 10 mg/kg = 100 mg/dose Maximum safe dose: 10 kg × 15 mg/kg = 150 mg/dose Ordered dose: 300 mg/dose Comparison: 300 mg > 150 mg (maximum) Conclusion: UNSAFE — the ordered 300 mg dose is double the maximum safe dose for this 10 kg patient. Setup (dimensional analysis): 22 lb × (1 kg / 2.2 lb) = 10 kg; 10 kg × 10 mg/kg = 100 mg (min); 10 kg × 15 mg/kg = 150 mg (max); ordered = 300 mg. Raw calculation: 22 / 2.2 = 10; 10 × 10 = 100; 10 × 15 = 150; 300 vs. 100–150. Rounding: Whole milligrams — no fractional remainder. Final answer: UNSAFE; hold the dose and clarify with the provider. Rationale: After converting to kilograms (10 kg), the well-known educational safe range for a single acetaminophen dose is 100–150 mg. The ordered 300 mg exceeds the maximum, so the nurse must hold the dose and contact the provider. Clinical pearl: Acetaminophen 10–15 mg/kg/dose is a commonly taught pediatric reference — verify the weight AND the dose against a range before giving any weight-based medication.

40. Question 40. Scenario: A nurse reviews a hand-written postoperative order that contains multiple elements on The Joint Commission "Do Not Use" list. Order: "Morphine sulfate 2.0 mg IV Q.D." Question: Identify every unsafe abbreviation or decimal error in this order and state how each should be rewritten to be safe.

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    Correct answer: Two unsafe elements: (1) "2.0 mg" trailing zero → "2 mg"; (2) "Q.D." → "daily" Setup (dimensional analysis): N/A — order-error identification and rewriting. Raw calculation: N/A Rounding: N/A Final answer: Rewrite as "Morphine sulfate 2 mg IV daily" Rationale: (1) "2.0 mg" contains a trailing zero; if the decimal is missed, "2.0" reads as "20," a 10-fold overdose. It must be written "2 mg." (2) "Q.D." is on The Joint Commission "Do Not Use" list because it can be misread as "QID" (four times daily) or "QOD" (every other day); it must be written "daily." The drug name is already spelled out in full (a best practice, since "MS," "MSO4," and "MgSO4" are also on the list), but the nurse should still verify the dose, route, and indication with the provider. Clinical pearl: Scan every order for the "Do Not Use" items — U, IU, QD, QOD, trailing zeros, missing leading zeros, and MS/MSO4/MgSO4 — and rewrite them in full before administration.