I have been studying differential equations (DEs), and have just recently investigated Euler's method for approximating solutions to DEs.
The DE of interest to this post is as follows: dy/dx = y
The solution to this DE is the standard exponential function e^x, so I thought, well when x=1, y would equal e, so I thought this would be a fun way to approximate e.
It's accurate to 4 decimal places, which isn't much, but it's an approximation after all. :P/>

Here it is in all of it's 30 lines of glory (half of which is a comment xD)

pastebin get zZ8U119B e


Thanks for reading! :D/>
~Incin