So true. I bought this book for my little one a few years ago. It follows a similar approach: Barter > Shells > Gold > Fiat > Bitcoin. 

https://www.amazon.co.uk/gp/aw/d/0578490676

Before teaching them about Bitcoin, teach them about the history of money. In their way of understanding or even in form of a game.
You will never truly understand what is bitcoin if you do not start with what is money.

DarthCoin

PowerPoint for your children? 

Never too early to get them ready for office space 

Make a PPT in which everything from the history of money to the discovery of Bitcoin is explained. And the current scenario has been explained.

BitcoinAbhi

These videos may help:

1. Season 2 Episode 3 (Bitcoin and the Beast) of “Tuttle Twins” features Bitcoin? The twins need to decide which is better when selling their dad’s old video game - Bitcoin or fiat.
2. Episode 3 of the new Futurama season features Bitcoin mining? In the episode "How the West Was 1010001," the main characters owed a debt to the robot mafia and were hence forced to travel West to "Crypto Country”.


cryotosensei

You're teaching a 1-day summer camp for kids (around 6-12 years old). You get 1 day to make as positive impact on their understanding of bitcoin and related subjects. What resources are you using? Keep in mind they likely won't have access to phones, but may have a laptop with internet connection.