I have been intermittently trying to teach my 6 year old niece calculus graphically. She can visually tell what the slope of the curve is and filling in the area under the curve is, well child's play. :-)
Basically, the idea is that you can introduce deep mathematical concepts very early by adopting a more intuitive media. Also, take a look at McLuhan[2] to understand how the media shapes the message if you really want to go deep into it.
[1] http://www.papert.org/works.html [2] http://en.wikipedia.org/wiki/Marshall_McLuhan
http://www.amazon.com/Mindstorms-Children-Computers-Powerful...