Hi there
What's the most simple way to describe what bitcoin is for people?
Will be cool to read in the comments some new creative ways to do that!

At 7 years old kid is not fit to teach about bitcoin because at young age they want to enjoy their life in playing. even if you teach them it is useless they don't understand what is it so may at 10 years old that's possible to the kids willing to understand what bitcoin is.