We can't normally teach kids about bitcoin. Why? First is that they don't know the value of money. They just sit around, play around, etc. They don't have the interest for the money. All they do is to ask their parents buy their wants or may I say toys which is the things they want so bad. If you can teach them, well it's great.
I think it's not time children understand about bitcoin, yeah true, even they may find it difficult to understand fiat money let alone understand bitcoin which is obviously more complicated than fiat. Little children it's time to play, learn, and will not be able to understand in detail about bitcoin
There is no certain time or age that bitcoin will be teached to kid, because if we teach them like in a school that's done step by step it's not hard for them to recognize and absorb the teaching. Although little children really needs to play, but I am not referring here to teach them like those older guys did and all I wanted to point out here is you know how to deal with them to merge bitcoin to their play times. Little by little information specially in schools might help them absorb those ideas about bitcoin, and by the time of their study development they already learned that spending is not just on fiat money but there's bitcoin also be considered as money.