One In A Million
This transparent globe is filled with about a million nonpariels (those tiny white sugar spheres that they sometimes decorate cookies and cakes with), all of them white except for one black one that is larger than the others and one black one that is the same size as the others.
This demo could be used at the very beginning of a general chemistry course when scientific notation and numbers of very large and small magnitude are being discussed.
For most people, a million is just too large of a number to visualize. This helps your class to realize that, although a million of anything is a lot, it is, after all, just another number.
"One In A Million" globe
The globe can be held up for students to see and they can be invited to come up for a closer look after class. It is probably best not to pass this demo around. It would be a major mess if it dropped and broke. You can challenge the students to try to find the two black nonpariels. The larger one is easy to find. The smaller one is more challenging, but not as hard as you might think. Most students are surprised to find out how easy it is to find "one in a million."