If you had 10 children, and each one of your children had 10 children, and this practice continued for 10 generations from you, how many descendants

WAY too many. I work on family trees as a hobby, and I have actually SEEN family trees just like this. The farm wife might have had 10 or even 14 children, and all of her children who lived were also prolific. It becomes very time consuming to fill in ALL their names and dates.