Khan Academy has 10 million students. They pay nothing. They are located all over the world.
Oakland Unity School in Oakland, California, is an inner-city charter school. It is over 90% black and Hispanic. It was a low achiever. Then it adopted Khan Academy’s math program. This school is now in the top ten schools in the state in math — in the 99th percentile.
Khan Academy teaches with YouTube videos and exercises. It also teaches motivation — character. Character makes the difference. IQ scores don’t.