Corrected: An earlier version of this story incorrectly stated the number of registered users of the Khan Academy. It is 137 million users. A bevy of technology and software tools are taking center ...

(CBS News) Sal Khan is a math, science, and history teacher to millions of students, yet none have ever seen his face. Khan is the voice and brains behind Khan Academy, a free online tutoring site ...

A big idea driving Khan Academy is a belief in “mastery learning”—that students should show proficiency in one set of materials before moving on to the next. The nonprofit’s latest push to make ...

Courses are well-designed, and most if not all instructors seem genuinely engaged and concerned with the outcome of the learning process. Courses are organized thoughtfully, with content presented in ...

"This," says Matthew Carpenter, "is my favorite exercise." I peer over his shoulder at his laptop screen to see the math problem the fifth grader is pondering. It's an inverse trigonometric function: ...