I've already managed to fail at my 250 words per day project, since I haven't posted in a while. That's alright I suppose, maybe it will take a bit of time to get into it. Anyway, here's another brief post about something I discovered the other day: a site called Project Euler. This site has a whole bunch of mathematical problems that you can solve via programming.
The fun part about this site is that many of the problems are fairly easily solvable using a recursive solution. I find that in everyday coding, you don't really do much development using recursive functions. This is disappointing because it really is quite an elegant way to solve problems! For example, problem 28 might not seem like a recursive problem, but in fact can be solved trivially using a recursive solution! I enjoy "games" where I begin to think in this way, maybe it helps stroke my nerd ego a little. On top of that, the focus is also on efficiency; it is possible for a computer to solve any of the problems within one minute (the one-minute rule) provided you're using an efficient algorithm.
Most of the problems, if not all, are based on work done by Euler. This includes problems involving prime numbers, combinatorics, factorials and other tasty bits of number theory. These are very useful bits of math to learn, and the harder questions on the site force you to do a bit of research in order to find a proper solution.