Personally I can't tell how thankful I am about Khan Academy because there are really mathematical concepts that I simply couldn't digest back when I was in high school mostly because I either got lost in 1-2 chapters (back then) and instead of understanding the concepts I ended up drowning in them.
You know what is even funnier? That after learning the logic behind programming I was able to perceive mathematical concepts under a whole different view and had so many fulfilling "oh that!" moments so far!
That is why our educational system should be based on capability and progress, not age, from grade one. Kids shouldn't be put in a situation where they will drown as it only sets them up for more difficulty later.
You know what is even funnier? That after learning the logic behind programming I was able to perceive mathematical concepts under a whole different view and had so many fulfilling "oh that!" moments so far!