I think that it is very important to teach kids about how to manage their own money, when they grow up. And bitcoin is a very good gateway to do exactly that, since bitcoin is without a central bank. They'll learn more about the economy.
I think the best way to teach kids about bitcoin is to give their allowances in BTC. Then they'll figure out how the whole system works.
Or maybe give them links to videos that explains bitcoins and how it works in a easier and explained manner. I think children would love bitcoins only if they find it easy to use and easy to earn.
At that age I don't think that they will find it easy, as even youngsters finds it difficult to understand it at initial stage so we cannot expect that kids will be interested in it.