Scrooge McDuck and Money (1967)

Huey, Dewey and Louie stop by to see Scrooge McDuck and ask for advice on making their savings grow; he tells them the history of money and the basics of economics. There's also a segment on how large a billion is, and another on budgeting (both personal and governmental). Amazingly enough, Scrooge is a big fan of putting money to work, not just stashed in a vault (he claims his vault is just petty cash that moves in and out daily). He then explains investing, and sells the boys a share of Scrooge, Inc.