Latex and Resin Help!

Hello again!
So I ended up scrapping my old head and I started to get into the swing of ordering more stuff. But the morning before I ordered my new balclava, my art teacher told us that our assaignment was sculpting an animal's head. I got all excited over the fact that I could make a resin head out of it! After a little research, I found out that the clay we used is sulfur free, which was a big bonus. I went ahead, ordered my stuff, and then I realized that the stuff I ordered requiered a gram scale! All I have is a scale that weighs in pounds. I recived my supplies and these are the scales: Smooth On Mold Max STROKE - 100A:10B, Smooth On EpoxAcast 690 - 100A:30B (Both measured by weight)
My problems:
a) I have no gram scale. Could I just convert the weight?
b) I really dont get the scale. DETAILED help here would be appriciated.