There is an interesting book on the subject called The Reverse of Spoiled
Interesting points are summarized here but the book goes extensively into details and there are interesting concepts about money killing internal motivation and replacing it with external money motivation which is not that good along the way. Money should be seen as a means to accomplish great things and not as an end goal. Also, the most important thing to teach kids is delayed gratification. Never be the first to buy the Nintendo switch, never be the last. The 60/40% rule. Let 40% of his friends have it first so he learns gratification and how to hold his money to know if your kid really wants it and then help him buy the basic cost and pay any extra to get a premium brand.
Nowadays it's important to teach our children the importance of money, and how to use them wisely from about 10 years old. For example, I am very thankful to my parents that they have taught me how to make money and their importance in my youth so even now during this difficult period I can live on my own without asking for help from someone. That knowledge that I have acquired from my parents in childhood helps me to pass through all the life which I meet. Now during this hard time, I decided to become a trader because thus I will be able to make money online. Now I am learning about contract specifications, and soon I hope to make more money.