I have used this GREAT, simplified, geography, math, & art activity for many years to show students rules of coloring maps. These pages were from the National Council of Teachers of Mathematics, NCTM Student Math Notes, 11/90.
Their website is filled with many other geography/math links, but I did not find this one that I've posted. However, page 4 gives permission to reproduce the activity for classroom use!
(double click on each image to enlarge and print)
More information on the 4-color theorem for coloring maps:
additional examples (worksheets): http://www.ctl.ua.edu/math103/mapcolor/mapws.htm