Chapter 7 - Measurement - 7.3 The Metric System - Capacity and Weight (Mass) - 7.3 Exercises - Page 500: 45

30 g

30,000 mg to g Unit for the answer (g) is in numerator; unit being changed (mg) is in denominator so it will divide out. The unit fraction is $\frac{1 g}{1000 mg}$. Multiply 30,000 mg times to the unit fraction 30,000 mg *$\frac{1 g}{1000 mg}$ = 30 g