Whether your kids go to public school, private or are home-schooled, this website is a gem. Sometimes our children have a hard time understanding math when we explain it or even their teacher at school. So the next time you are stumped go to Khan's Academy.
This man made youtube videos from basic addition to calculus.
Here is the link
The Khan Academy is a not-for-profit 501(c)(3) with the mission of providing a world-class education to anyone, anywhere. Despite being the work of one man, Salman Khan, this 1600+ video library is the most-used educational video resource as measured by YouTube video views per day and unique users per month. We are complementing this ever-growing library with user-paced exercises--developed as an open source project--allowing the Khan Academy to become the free classroom for the World.