The Khan Academy is a non-profit organisation hosting more than 4,000 video tutorials in subjects like mathematics, healthcare, medicine, finance, chemistry, biology, astronomy and more. The site, which aims to provide high quality education for anyone, anywhere, is backed by industry heavyweights such as Bill Gates and Google.
- To view videos only:
Log onto the local mirror, http://khan.uct.ac.za, to view the entire Khan Academy video library.
- To do exercises and track your progress:
Use the full version at https://www.khanacademy.org.