Gilbert Strang’s linear algebra lectures, from M.I.T., are among the most watched courses on the Web.

Gilbert Strang is a quiet man with a rare talent: helping others understand linear algebra. He’s written a half-dozen popular college textbooks, and for years a few hundred students at the elite ...

Strang’s linear algebra lectures have more than 4.7 million views on YouTube. READ MORE: WWII vet, 101, 'finally' walks at graduation 80 years after having to miss ceremony amid global war ...