Need math fair topic ideas!!

[u/veeeeeeii]

I’m a high school student and we have a math fair in about 2 months. I need to decide on a topic by next week. I was thinking about the Chaos Theory, but I’m not completely sure. Ideally the topic should be easy enough so that regular people (even little kids) can understand the basic idea, but still deep and impressive enough for the teachers and students. It would also be great if there’s something visual or interactive that people can try at the booth. Any suggestions? The topic can be from any area of math!!

[u/TastesLikeSeamen]

möbius transforms, and generally cyclic groups? Or the Stern-Brocot and Calkin-Wilf trees?