I came across this post at Metamodern discussing a very interesting, and utile, online resource — Khan Academy. If you’re looking for short, to-the-point online lessons (more than 1000) on mathematics ranging from basic arithmetic and algebra to differential equations, physics theory, chemistry, biology and finance, this is a great resource.

From the first link:

I got a pointer to a free, online educational resource today.

It deserves more attention.

The eyeballs of a few million students might be a good start. Students in elementary school, grad school, rural Africa… places like that.

It consists of 1000+ brief lectures on YouTube.

It centers on math, but goes beyond.