So I offer them small Bitcoin piggy banks where they can deposit their coins. Once they accumulate some dollars, they can acquire their first sum of satoshis, finally starting their investments for real. It's also an interesting concept for children to save their daily changes and invest in BTC later, thinking on their future.
While it is true that this might not be of any significant to the adoption of Bitcoin just as others have said but I must commend you for your effort, and also the concept you employed.
The Piggy Bank gives them the ability to also save their money without relying on any middleman to save it for them and they can choose to withdraw and spend their money anytime they like, it's quite interesting if you look at it from this perspective.