Question

Use a proportion to convert 18 grams to milligrams. [Hint: 1,000 mg = 1 g.]

Answer 1

x/18=1000/1
18000=1x
18000mg

Answer 2

Our proportion would be: 

$\frac{1g}{1000mg} = \frac{18g}{x}$

We would then cross-multiply and our answer would be 18,000 milligrams.