A penny is the smallest unit of American currency, worth one cent or one-hundredth of a dollar. If you have 100 pennies, you can exchange them for a single dollar bill. The copper-colored coin features Abraham Lincoln's profile on one side and the Lincoln Memorial (or, on newer pennies, a shield) on the other.

Many people keep pennies in jars at home because they're too heavy and bulky to carry around for their small value. Some stores now round prices to the nearest nickel because pennies are less commonly used.

The phrase a penny for your thoughts means you're curious what someone is thinking about. If something costs a pretty penny, it's expensive. When you're penny-pinching, you're being very careful with money. And if you say someone is penny wise and pound foolish, you mean they're saving small amounts while wasting large ones, like someone who refuses to buy a quality winter coat and then spends far more money on doctor visits for repeated colds.

Small amounts can add up over time. Benjamin Franklin's saying a penny saved is a penny earned suggests that avoiding waste matters as much as making money.