https://www.khanacademy.org/

-Free online learning is available in a variety of subjects, including math, biology, chemistry, physics, finance, and history. There are short video clips on each subject as well as interactive exercises that allow students to practice their new skills.

http://www.starfall.com/

-On this homeschooling website, started as a free interactive way to teach young children to read using phonics, kids can play games, watch short videos on letters and sounds, and flip through "books" of stories.

http://www.duolingo.com/

dir="ltr">- to learn languages