Kids can be taught about bitcoins with reference to gold as how we buy gold and store it and sell when prices are high. This should work for the trading aspect, while using bitcoins as online money can be taught much easily because kids today are very much into technology and internet. They can understand the concept of Digital money quite easily because they are still in learning stage and thus will grasp easily.
I dont know, but this doesnt seem to be a good idea. Theyre still kids and I dont see any reason you should be teaching them something that is far much above their level of understanding. There are more important things you should be teaching kids at a young age, and Im sure its not to be money minded, but to have manners, respect, knowledge and the fear of God. Wait for them to grow up to a certain age, then you can start teaching them about Bitcoin, and by then things will be very easy.