Jacob and his family went to Egypt numbering (approximately) 70 people. After approximately 200 years, 600,000 men between the ages of 20-60 (if I'm not mistaken). So probably 2 million total got out (this is an estimate I've heard). The highest estimation(Rashi, I think) is that 20% got out from Egypt, so by that estimate there were 10 million Israelites in Egypt at the time of the Exodus. And this was a generation after Pharaoh decreed that all the Israelite baby boys be killed.
My question: How is it possible that 70 people in 200 years multiplied to 10 million?