Occupation: Founder and executive director, Khan Academy
In the past few years, Khan has been called the messiah of math, the world's teacher and a revolutionary. That's a lot for a guy who got his start by posting videos on YouTube to help his cousin with her math homework. Those original videos and thousands more like them now reach up to 4 million students worldwide every month as part of the Khan Academy, a nonprofit dedicated to providing a world-class education to anyone, anywhere.
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