Slightly off-topic, but I can not recommend Khan Academy highly enough. Between the directed learning and the helpful videos, I am working to improve my kids understanding of maths and usually don't lose my temper. Prior to that, it was a frustrating exercise for everyone involved.
I’d love to see the minutes spent map per capita.<p>As is it would be largely impacted by population. <a href="https://xkcd.com/1138/" rel="nofollow">https://xkcd.com/1138/</a>