I think we can start explain bitcoin by tell them that bitcoin is like other international currencies dollar, euro and many else. They will understand and you explain more about bitcoin.
I agree. we should teach and explain them in simple way.. going to deep details may cause their mind more confuse about bitcoin.
so the best way is to just tell them bitcoin is a currency and it can be use via internet to buy things and it can be earned for free by doing small jobs and works.
Teenagers are smart enough to understand bitcoin.
I don`t know what`s the point of explaining bitcoin to children.
They just won`t use btc because they are still woung and don`t need money.
They have parents to give them money.

the point is not that kids don't need money or bitcoin..but tthe point is kids should know about bitcoin specially a teenage kid who's age is above 15 should know about bitcoin because bitcoin is money of futre I believe.