I was actually wondering if there are any restrictions on age as to investing in Bitcoin?
In general, I would recommend 18 or 19 years. I think age has been used by most countries to mean someone is mature and can be held accountable for what they do. Even so, for someone who has an interest in bitcoin since childhood can start investing at the age of 15 by setting aside his school pocket money, but in my opinion that is a rare condition.
To be honest, I don't agree with the concept of teaching bitcoin to kids under the age of 10. I think it's a pointless thing and bitcoin is not important to them. Maybe teaching mathematics would be more beneficial to support their learning at school.
Most importantly, if the child is under 18 years of age, I think he or she will need the help of a parent when he or she is going to try to start investing in bitcoins. In addition, buying bitcoins on exchanges also mostly requires kyc, and maybe exchanges will refuse kyc for children under 18 years old