Carlos Slim Helu vs. Michael Bloomberg

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.

In 2018, Bloomberg pledged $1.8 billion to Johns Hopkins University, his undergraduate alma mater, adding $1.5 billion he had already given the school. As a teenager, Bloomberg worked at an electronics company in Cambridge, Massachusetts.