Online Financial Calculators
Bankrate offers dozens of financial calculators. http://www.bankrate.com/calculators.aspx
When I look at them, I think: "A business professor could teach half a dozen business school courses based on these calculators."
A person who really knew how to put them to effective use would have a comprehensive education on personal finance.
A young married couple might avoid the lobster trap of lifetime debt if their parents had used these tools to teach them the basics of the personal debt.
Lenders know that their targets have never used any of these tools. They set the traps early. "Try it. You'll like it."
There are no free lunches. Count the costs.