children doesn't need to know about currency,but teenagers does,and i think there's so many explanation video in youtube so don't wasting effort wasting your time when you can just give them about the link of video so they can learn from it,whether they will be interested or not,it's definitely depend on them
you are probably right and besides teenagers now a days are very smart already.even if we are not going to teach them tgey will probably know about bitcoins through social medias and youtube and even with their friends.