For some reason I felt like this was relevant Happy Pi Day! The digits of the date - 3.14 - contain the first couple digits of π. But that's not all. If you add the year to get 3.14.16, you have the first 5 rounded digits of π. This is better than last year's version (3.14.15), which contained a truncated version of π. Today's date contains the more accurate rounded version. In this post, I'll describe the process of finding an algorithm to approximate the number π. There are three main types of algorithms. The first type converges very quickly to the correct solution; we use algorithms of this type in computers and calculators. The second type converges slowly, but is interesting to think about; we take this type of algorithm to mathematics conferences. The third type is slow to converge, and is boring to think about; these are pretty much useless so we get rid of them. This may be interesting to know, but I wasn't too worried about it when I wrote my Pi Day post l