A world-class tutor for the digital age

摘要

Like a lot of great innovators, Salman Khan didn't set out to change the world. He was just trying to help his teenage cousin with her algebra from across the country. But from a closet turned office in his Silicon Valley apartment, Sal, 35, has produced an amazing library of online lectures on math, science and a host of other subjects. In the process, he has turned the classroomand the world of education-on its head.