Chapter 1 Units, conversions and rounding Learning goal: Convert confidently between metric, household and time units and round the way the NCLEX expects. Every calculation fails if the units are wrong. Memorise the core conversions below until they are automatic; the exam provides an on-screen calculator but not a conversion chart. From; To; Equivalent; 1 kg; lb; 2.2 lb; 1g
mg; 1,000 mg; 1 mg; mcg; 1,000 mcg; mL; 1,000 mL; 1 tsp; mL; 5 mL; 1 tbsp; mL; 15 mL; 1 oz; mL; 30 mL; 1 cup; mL; 240 mL; 1 hour; minutes; 60 min
Metric staircase: each step down = multiply by 1,000 kilogram - 1,000 g; kg; gram - base unit; g; mg; mcg; milligram - 1/1,000 g; microgram - 1/1,000 mg
Figure 1.1 Moving down the staircase multiplies by 1,000; moving up divides by 1,000.
Rounding rules • Round only the final answer, never intermediate steps. • Tablets: round to the nearest half tablet only if scored. • mL for adults: nearest tenth (0.1 mL). Volumes under 1 mL: nearest hundredth (0.01 mL) using a tuberculin syringe. • IV pump rates (mL/hr): nearest tenth if the pump allows, otherwise whole number. Gravity drops (gtt/min): always a whole number. • Weight: convert lb to kg and round kg to the nearest tenth before calculating.
Educational use only. Verify against current facility policy and drug references. Not real NCLEX items.
SAFETY ALERT Never write a trailing zero (5.0 mg can be misread as 50 mg) and always write a leading zero (0.5 mg, not .5 mg). Both rules come from ISMP error-prone abbreviation guidance.
Educational use only. Verify against current facility policy and drug references. Not real NCLEX items.
Chapter 1 study page: Units, conversions and rounding Use this page to consolidate the chapter before attempting the questions. Writing the answers from memory (active recall) is one of the most effective study strategies. In your own words, summarise: Rounding rules.
What is the single most dangerous finding in this chapter, and what is the first nursing action?
Which medication, lab value or number from this chapter must you memorise? Write it with its unit.
Create one NCLEX-style question of your own on this chapter and explain the correct answer.
Check your understanding Q. A client weighs 176 lb. What is the weight in kilograms? A. 70 kg B. 80 kg C. 88 kg D. 387 kg
Educational use only. Verify against current facility policy and drug references. Not real NCLEX items.
Sample shown: about 423 of 4,551 words.