Salman Khan is a math and science whiz kid, and a natural-born teacher, who is now devoting his life to tutoring people around the world using YouTube videos.

He left his job as a hedge fund analyst in Boston three years ago. His YouTube channel, called Khan Academy, now has 1000+ videos covering everything from basic arithmetic and algebra to differential equations, physics, chemistry, biology and high finance — all of which were recorded by the affable Khan.

It started as an online tutoring session for his cousin to help her gain pre-algebra admission, and led to a not-for-profit corporation dedicated to the mission of providing a high quality education to anyone, anywhere.

"With so little effort on my own part, I can empower an unlimited number of people for all time," Mr. Khan told the San Francisco Chronicle. "I can't imagine a better use of my time."

The entire video library is listed online and offers instruction for free with just a click of the mouse at www.khanacademy.org. Subscribe to his videos at YouTube, here.

(WATCH how it all started below)