ELI5: Explain Like I'm 5

Five color theorem

Okay kiddo, let me explain the Five Color Theorem to you in a way that you can easily understand.

Do you like coloring? Imagine you have a big map of your favorite country with lots of different regions. Now, you want to color each region in a different color, but you don't want any regions that share a border to have the same color.

Sounds easy, right? But what if there are lots and lots of regions and it's getting hard to keep track of which colors you've already used and which borders you still need to avoid?

That's where the Five Color Theorem comes in! It says that no matter how many regions you have, you will never need more than five different colors to color them all in such a way that no two neighboring regions have the same color.

So, if you have a map with a hundred different regions, you could still color them all with just five colors and be sure that there are no two neighboring regions with the same color. Pretty cool, huh?

This theorem was first proven in 1890 by a man named Percy Heawood and is still used by cartographers and mathematicians today to help them solve complicated coloring problems.
Related topics others have asked about: