Rule 1 - always use a leading zero
For any amount less than 1, write a zero before the decimal point:
Write 0.5 mg - never .5 mg.
Without the zero, a hurried reader can miss the decimal point entirely and see ".5" as "5" - ten times the intended dose. The leading zero makes the decimal impossible to miss.
Rule 2 - never use a trailing zero
For a whole-number dose, do not add a decimal point and a zero:
Write 5 mg - never 5.0 mg.
If the decimal point is missed, "5.0" is read as "50" - again ten times the dose. A trailing zero adds no information and only invites error.
How DoseDrill enforces this
Every generated dose, every worked step, and every calculator result is passed through a formatter that guarantees a leading zero and strips trailing zeros. So the numbers you practice with always model the safe habit you will use at the bedside.