PTCB Math Practice Exam - Prep & Practice Questions Study Guide

To convert milligrams (mg) to grains (gr), you can use the conversion factor that 1 grain is approximately equal to 64.8 mg. To find the equivalent of 360 mg in grains, you would use the following calculation:

1. Start with the amount in milligrams: 360 mg.

2. Divide this number by the conversion factor (64.8 mg/gr):

\( \text{Grains} = \frac{360 \text{ mg}}{64.8 \text{ mg/gr}} \)

3. Performing this calculation gives you approximately 5.56 grains.

This result (5.56 grains) is the correct conversion from 360 mg, making it the equivalent value expressed in grains.

Understanding conversions like this is key in pharmacy, where dosing and formulations often require precise measurements in different units.