Over at the Emacs subreddit, _DonK4rma shows an example of his mathematical note taking in Emacs. It’s a nice example of how flexible Org mode is even for writing text with heavy mathematical content but probably not too interesting to most Emacs users.
What should be interesting is this comment, which points to Dan Davison’s Xenops, which he describes as a “LaTeX editing environment for mathematical documents in Emacs.” The idea is that with Xenops when you leave a math mode block it is automatically rendered as the final mathematics, which replaces the original input. If you move the cursor onto the output text and type return, the original text is redisplayed.
It’s an excellent system that lets you catch any errors you make in entering mathematics as you’re entering them rather than at LaTeX compile time. So far it only works on .tex files but Davison says he will work on getting it to work with Org too.
He has a six minute video that shows the system in action. It gives a good idea of how it works but Xenops can do a lop more; see the repository’s detailed README at the above link for details.