One Penny, Two: How one penny became $41,943.04 in just 23 days.

"It's a magic box. If you put a penny in the box and don't take any out, they will double each day," Joe told Jerry. "If the penny doubles each day," wonders Jerry, "how long will it take to buy a dark green convertible sports car? "Will Jerry be able to keep the pennies in the box until it is enough? This exciting tale shows the power of doubling.