This 'Swiss-cheese' gap in her knowledge was not allowing her to be placed in the more advanced math track.

In August 2004, Sal Khan began remotely tutoring his cousin, Nadia, who was struggling with unit conversion. Sal is a former hedge fund analyst with degrees from MIT and Harvard. His mother was born in Calcutta, India and his father was born in Barisal, Bangladesh. Sal was born and raised in New Orleans, Louisiana. In addition to creating our online materials, we also translate our materials into the world's most spoken languages and work with schools on innovating how learning is done in the classroom. You can earn points and badges along the way, and coach others as well. With thousands of bite-sized videos, step-by-step problems, and instant progress information, Khan Academy provides a rich and engaging learning experience. Our online material cover subjects ranging from math and finance to history and art. Our mission is to provide a free, world-class education to anyone, anywhere. Khan Academy is a not-for-profit educational organization started by Salman Khan in 2008.

Salman khan education website