Reconstitution math walkthrough + the 3 mistakes I see most

since the calculator gets used a lot, here's the method plus the 3 errors I see most. concentration (mcg/mL) = vial mg x 1000 / mL of bac water. volume for a target = target mcg / concentration. doing it by hand once makes it stick.

the three mistakes: (1) mixing mg and mcg in the same step, (2) forgetting U-100 syringe "units" are hundredths of a mL, so 0.05 mL = 5 units, and (3) thinking more water is "safer" when it just changes the concentration. this is arithmetic only — says nothing about whether to use anything.