Except there isn't agreement on the definition of "money" (because it's more complex than it seems on the surface), and there isn't agreement on how it works.
Agreed, but the point of (good) education is not inject revealed truth but train people to think. The different "definitions" are in reality different social contracts so there is nothing to agree on (but one can question which types are more appropriate for what type of economy etc).
Maybe, but this isn't elementary school stuff. It's complicated. To really understand it requires some knowledge of law, business, finance, human psychology, math and history. There is a good reason it's so misunderstood.
Elementary school was mostly a figure of speech. It should really be an ongoing learning track, starting as early as possible. I think in gamified and simplified form one can definitely setup trading games and the like and "get them while they are young". Later adapted to the cognitive abilities of each level. Content is not strictly just about monetery systems: a number of other core concepts from economics and law / contracts in particular.
The bottom line is that modern society is absolutely obsessed with money and knows practically nothing about it. Not a good combination.
