This project can be done in any class, but lends itself well to elementary and middle school classes best. The task is simple, everyone in the class (teacher included) looks for examples of math in their day to day lives and records those examples as they find them. This is not intended to teach students the mathematics, although the examples students find may work as a good hook for a lesson, but to teach them that math is part of their world.
Here’s a Flickr group you can use to have your class share their examples with a wider group.