Elementary school is not a suitable place to teach financial literacy in my opinion. I don't know, but I think every country must have lessons about the economy, right? Doesn't that include the basis of financial literacy as well.
There are already countries doing that, you don't need to teach the whole kids just learn the basics, most first world countries do that like Denmark, Australia, Canada, Germany and US, and what its more its effective. And economy subjects is teach in secondary school or specifically college already
I agree, just the basic for them to start learning. Also, kids nowadays are smart and it is easy for them to learn. They also have all the access they needed to learn (youtube and other social media platform). As long as they are interested in learning, there will be no issue and they will learn as much as they want.