Chapter 7 - Measurement - 7.3 The Metric System - Capacity and Weight (Mass) - 7.3 Exercises - Page 503: 51

0.003 kg

3 g to kg Unit for the answer (g) is in numerator; unit being changed (kg) is in denominator so it will divide out. The unit fraction is $\frac{1 Kg}{1000 g}$ . Multiply 3 g times to the unit fraction 3 g * $\frac{1 Kg}{1000 g}$ = 0.003 kg