1. No worries, apology more than accepted :). 2. Good call. Math Wars is the longstanding problem, these skirmishes are the latest battle. Definitely not clear

1. No worries, apology more than accepted :). 2. Good call. Math Wars is the longstanding problem, these skirmishes are the latest battle. Definitely not clear to the unfamiliar reader. I'll have to think how to reword it. 3. Thanks for the clarification. I write "Bad Teacher < Online Learning < Good Teacher" in the sense that a static video [or article] can't react to your confusion, explain a different way, etc. the same way an in-person teacher can. But Khan is in no way a bad teacher, and is probably in the 90th percentile of math teachers (probably the 99th percentile in terms of math background, after doing all the lessons for Khan Academy). 4. Awesome! You might like the following article on imaginary numbers, there was a great discussion on HN: http://news.ycombinator.com/item?id=2712575 http://news.ycombinator.com/item?id=2712575