Don't use that ten to pay for your lunch without giving it a second look. Knowing which 10-dollar bills are worth money can help make sure you don't trade a treasure for your tuna sandwich.

It's pretty normal to get a fiver back when you get change, but some rare 5-dollar bills are actually worth a lot more than ...

Pull any bill ... it may be worth much more than face value. In fact, collectors are often willing to pay big bucks — hundreds or even thousands of dollars — for rare paper money.