posted a cleaner, formatted version to --
* https://medium.com/@DesignAllthings/ask-hn-learning-math-practically-examples-from-real-life-links-inside-2ea752f8c5d7
--
2000 characters limit....
* https://pastebin.com/rnywXAVh
* http://textuploader.com/druk9
uploaded to both