Sal Khan teaches math, science, and history to millions of students, but none has ever seen his face.
Khan is the voice and brains behind the Khan Academy--a free online tutoring site that was born out of a young cousin's struggles with algebra in 1994. His classroom has grown from a few hundred pupils to more than 4 million a month.
Khan, 35, believes he can transform education worldwide, and his approach is now being tested in American schools. Along the way, the former hedge fund analyst has won the support of Google Chairman Eric Schmidt and Microsoft co-founder … Read more