My recent email conversation with Marilyn Just about the Art of Problem Solving website. Reminded me of a great source of fun mathematics pictures to use in the classroom. The Bad Maths Flickr group contains lots of examples of bad math spotted in stores and other public places. Some of the bad math is obvious as in this picture taken in a Walmart store. Other examples are not as obvious.

cc licensed ( BY ND ) flickr photo by Danny Nicholson: http://flickr.com/photos/dannynic/6363183821/

Applications for Education
The Bad Maths Flickr group could be a good place to find some images that contain simple mathematics problems for your students to solve. For example, ask students to find the flaw in the math of this grocery store offer or this offer for cat food.