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. Children might be somehow get bored when you just plainly explain what it is. However there can be some solution for that like making a visual aids to teach Bitcoin through animations and interactive videos to make it eye-catching and it will catch their interest to listen and follow the lessons being taught.
That is the best way to teach children. You have to do a variety of creativity and innovation so they understand bitcoin easily. If they can understand the bitcoin from the beginning then I'm sure it will be easier for them to understand as adults. But do not take the time to play children too long. You should be able to estimate the right time in giving them lessons.
The best way to explain bitcoin to kids is by given them sensible examples.
You can start by telling them; bitcoin is currency just like USD but digital like online ebook.
People buy and sell things online with bitcoins just like the way they do it with regular USD.
The next thing, then you should explain them how to store bitcoin in online wallets just like bank account.
Remember, they are kids you shouldn't have to get any deeper when explaining the concept of bitcoin to them.
I think that way the kids would understand everything you are trying to teach them.