Large numbers are hard to comprehend. It helps to visualize them in terms of a familiar, everyday object, like a U.S. penny. That’s what the MegaPenny Project does. It starts with a single penny and shows you visual representations of increasingly large numbers of pennies. For example, how big is a hundred thousand pennies? (It’s about two cubic feet.) What does a billion pennies look like? How many would it take to fill up the Sears Tower? If you could collect all the pennies that actually exist, how large a stack would that make?
For each big number, the MegaPenny project not only shows you a picture, but also lists statistics like the monetary value, the total weight, the height (if you stacked them in a single column, one penny on another), and the area covered (if you laid the pennies out edge-to-edge). The site takes you all the way to one quintillion pennies (a cube about five miles on a side).