Metric units and conversions
2 marks of the 15 in Part A, which runs for 30 minutes.
Every conversion in this section moves the decimal point three places, and a slip of one place is a tenfold or thousandfold drug error. That is why the NMC tests it on its own rather than only inside dose calculations.
What this section asks about
- Grams to milligrams to micrograms, and back
- Litres to millilitres
- Conversions inside a dose calculation, where you convert first and divide second
- Reading a prescription written in one unit against stock labelled in another
Where the marks go
2 marks of the 15 in Part A, which runs for 30 minutes.
Every numeracy question sits at the apply and analyse level: you are given a situation and asked to work something out, rather than to recall a fact.
Where candidates lose marks
- Moving two places instead of three. There are 1000 micrograms in a milligram, not 100.
- Converting after dividing rather than before. Get both figures into the same unit first.
- Writing microgram as mcg or ug. UK practice is to write it in full, because the abbreviations are misread.
Questions people ask
- Which units does the CBT use?
- Metric, as UK practice does. You will not be asked to convert pounds to kilograms or fluid ounces to millilitres.
- Should I write micrograms in full?
- Yes. Abbreviating it is a recognised source of drug error, and the safety guidance is to write micrograms out.
Practise this section
Practice is filtered by section, so you can work on this one on its own. Every account gets 10 new questions a day without a card.