Kahn Academy is a free world-class education for anyone anywhere.

They are a not-for-profit with the goal of changing education for the better by providing a free world-class education for anyone anywhere. All of the site's resources are available to anyone.

Students can make use of their extensive video library, interactive challenges, and assessments from any computer with access to the web. Over 3300 videos that cover K-12 math, science topics such as biology, chemistry, and physics, and even reaches into the humanities with playlists on finance and history.

Web pages from above with visible url links

• Khan Academy - https://www.khanacademy.org/