Coloring (The Four Color Theorem) This activity is about coloring, but don't think it's just kid's stuff. This investigation will lead to one of the most famous theorems of mathematics and some very interesting results.
The four color theorem was proven in 1976 by Kenneth Appel and Wolfgang Haken. It was the first major theorem to be proved using a computer. Appel and Haken's approach started by showing that there is a particular set of 1,936 maps, each of which cannot be part of a smallest-sized counterexample to the four color theorem.There are meaningful generalizations, if you consider surfaces like sphere, torus, Möbius band etc. as "3D objects". The minimum number of required colors for the mentioned surfaces is 4, 7 and 6, respectively.