The CBC’s Paul Hunter visits with Sal Khan, whose whimsical yet effective educational videos on YouTube have sparked what some are calling a teaching revolution.

Khan, a former hedge fund analyst, began nine years ago by making some simple videos for his young cousins, who were having trouble in math. The videos were a hit, not only with his cousins, but many others on YouTube.

Since then, Khan and his educational non-profit organization in Palo Alto, Calif., have produced more than 4,000 free videos on a wide range of subjects — math, chemistry, history, art and astronomy among them — that have garnered more than 250 million views in a few years.

As well, the Khan Academy produces software that allows teachers to closely monitor progress of students working independently on laptops. The students also consult with Khan via the YouTube videos when they like.

"His gift is to explain things in such a way that kids don’t just memorize it, but actually understand it," says Hunter.

"If you don’t get it, pause, rewind and listen again." That, says Khan, is the whole idea.