Carlos Slim Helu vs. Bill Gates

Every Sunday, Slim's father would give him a 5-peso allowance and required him to record his purchases in a ledger. Before going into business, Slim taught algebra at UNAM, a university in Mexico City.

When Gates was a kid, he spent so much time reading that his parents finally forbade him from bringing books to the dinner table. Gates took a break from classes his senior year in high school to do programming with his friend Paul Allen at a power plant in North Bonneville, Washington.