this link to see what you're missing. Khan Academy is an educational organization with a website that hosts over 3500 micro lectures teaching mathematics, history, healthcare and medicine, finance, physics, chemistry, biology, astronomy, economics, organic chemistry, American civics, computer science, test prep, and more. I'm serious! Their mission is to provide high quality education to anyone, anywhere and they are well on their way. Khan Academy has delivered over 200 million lessons. Along with the video library, the site also has 378 automated practice exercises, mostly in math.
For over a year we've utilized Khan Academy in some manner to compliment our homeschooling. We've either assigned certain lectures and assignments for our children to complete, or we've given them a time limit to spend on the site and allowed them to find, listen to, and report on lectures that interest them.
If you are a homeschooler, I would suggest becoming familiar with this site. If you are an individual who believes you are never to old to learn (like me!), I also suggest becoming familiar with this site. I waste all kinds of time on the internet, but not when I'm visiting Khan Academy.