and we asked you, what age is appropriate for a child to get an ipad at philly wattski tweeted, firstn i afford it then give it to them one year after they stop throwing things on the floor. that would be about 4 years old. and i am republican at 79 who apparently is a republican says when they're old enough to pay for it themselves with money they earned by working. okay, that's not about 4 years old. and ronald brandt also facebooked, my wife teaches 3-year-olds, and she uses them in class. i'm joined now by sal ckahn, founder of the kahn. sal, your business is about linking technology in the classroom. is there a limit to how much technology a child should be exposed to? >> yeah, there's a limit to how much of anything a child should be exposed to. even reading a book is a great thing. but if a child sits and reads a book for 12 hours a day and doesn't play with peers, it's an issue. and you have the same thing with technology. >> what do you think about the age for an ipad? somebody who wants to know what is an appropriate age for a child for christmas, assuming you don't put it o