Field Guide to Math in Humboldt
​No. 19  School Maps  &  Four Color Maps 

A group of volunteers is repainting the Alice Birney School's US state map. The map is being repainted with several colors, but it could be done with only four!
Four Color Map Theory Links 
http://gwydir.demon.co.uk/jo/games/puzzles/map.htm
https://www.youtube.com/watch?v=ANY7X-_wpNs
Picture
​Source:  https://calebstanford.com/2017/05/21/four-color-theorem/