In today's children are very easy to teach especially when it comes to online they can easily learn. You just teach them about bitcoin and how to earn it is easy just to tell them that bitcoin is cryptocurrency that you can convert it into cash and you just guide them right until they learn.
I agree with you. Today there is already a lot of teaching material about the crypto currency. You can just choose a video for Youtube, which tells about bitcoin. Children will look at the video and everyone will understand