During NHS nursing interviews, interviewers commonly ask you drug dosage or medication calculation questions to test your competency. Some questions may be more challenging than others, and the interviewers might even supply you with a pen and paper. This question should be quite simple for you to answer as an experienced nurse, as you will move the imaginary decimal point at the end of 1575 over three spaces to the left. (1575 micrograms ? 1,000 1.575 mg, or 1 microgram 0.001 milligram)