A savings account is an excellent way to learn about the power of compound interest works bypaying interest on interest. So, for example, one dollar invested at two interest(复利). Interest rates on savings can be very low these days. But compound percent interest willearn two cents in the first year. The second year, the money will earn two percent of onedollar and two cents, and so on. That may not seem like a lot. But over time it adds up.