i think the kids will learn about bitcoin in the same way as they learn about fiat so if we teach that bitcoin is also a currency and is working the same as fiat and teach them about the use of bitcoin in different places then they will star to use bitcoin as they are using fiat
they would understand just about bitcoin like fiat, if you tell them more about how bitcoin or on rate fluctuations or something, they will not know about it
I don't think that kids will be interested in knowing bitcoins at that early age as those are the days to have fun and entertainment so if we try to explain them about bitcoins then they will surely find it complicated and will not be interested in using it.
Then don't explain it or teach the complicated parts, just like what Blackstorm said let them learn the same way
we learn about fiat, teaching kids about bitcoin doesn't mean they have to know everything about bitcoin in
the young age, just letting them know about bitcoin can be used just like fiat is enough for their age.