MathJax for the win.

Just a little note that I use MathJax for my mathematical posts, and this is the ONLY scripting (so far) that I throw into my blog.

Here are some of the resources I use for MathJax:
http://meta.math.stackexchange.com/questions/5020/mathjax-basic-tutorial-and-quick-reference
http://www.suluclac.com/Wiki+MathJax+Syntax

and here's how I add it:
http://mathjaxtest.blogspot.com.au/
The one thing missing in this post, however, is that you need to close the </script> tag. :/

Why does e = 2.71828183? Or how e SHOULD have been discovered.

This is an interesting exercise to do with higher level mathematical students - it shows them that the value of $e$ can be derived purely from it's differential properties.

So we start with the fundamental property of $e$, that $D(e^x)_x = e^x$.
In short, we're looking for the identity function of differentiation - what function stays unchanged.
(As noted in previous posts, I'm using a differential format similar to sagemath's default format.)