If a patient is prescribed 1/4 grain, how many milligrams would that be?

To convert grains to milligrams, it's important to know that one grain is equivalent to approximately 64.8 milligrams. Therefore, when a patient is prescribed 1/4 grain, this can be calculated as follows:

1. Determine the milligram equivalent of one grain, which is about 64.8 mg.

2. Calculate 1/4 of that amount:

( 1/4 \times 64.8 \text{ mg} = 16.2 \text{ mg} ).

While the closest standard conversion often used in medication administration rounds this value to approximately 15 mg for practical purposes, the exact math yields 16.2 mg. This is why the correct answer is considered to be 15 mg, reflecting a common rounding practice in the medical field to simplify calculations for medication dosages, particularly in situations where precision to the exact decimal may not significantly affect patient safety.

It's useful for a medication aide to remember these conversions and rounding practices to ensure they are administering the correct dosages effectively.