All products featured here are independently selected by our editors and writers. If you buy something through links on our site, Mashable may earn an affiliate commission. Khan Academy's math lessons ...

The following script is from "Teacher to the World" which aired on March 11, 2012, and was rebroadcast on Sept. 1, 2013. Sanjay Gupta is the correspondent. Denise Schrier Cetta, producer. Take a ...

"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: ...

(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 ...