Over the past decade, the free instructional website Khan Academy has transformed how tens of millions of students across the globe perceive and approach math. Now, it’s pursuing a bigger aim: ...

Where should you go online to advance your understanding of a topic or study something new? For academic subjects, start with the excellent Khan Academy. It's one of the best online learning services, ...

In 2006, Sal Khan started making YouTube videos meant to help his nieces with their math homework. Since then, Khan’s video collection has grown into a huge repository of tutorials used in and out of ...