If you are going to teach it with the child who is 7 year old, you are going to use the word that can easily understand or comprehend them, but it really depends on the child if the child is not interested they will not easily understand it coz we all know that age is not the age that a child will give time to understand it. There is a child who are very curious but only few.
I agree with this explanation. How can you teach a child about bitcoin if he / she is not interested on the topic itself? So, in my own idea about this, if you are teaching a 7 years old child about bitcoin you may used any strategy or a technique that can catch his or her attention. It may be a kind of game, a puzzle that is connected to bitcoin.