I know this one from experience. Cool math is a term that is very rarely used because most people do not like math so how can something disliked by people be fun. All I can say is play games. It is hard to tell but almost every board game uses math in someway. It may be scoring, or it may be the theme of the game. All in all it is just a way to have fun. Science proves that even if you are doing math subconsciously it is still practice needed to make progress in learning.