Let’s start by considering math majors in college. Except for the “best of the best,” it’s been my experience that most 3rd or 4th year math majors don’t understand half the stuff they’ve studied, nor do they have any notion as to how deeply connected the different branches of math truly are.
Okay -- the problem I would like to see solved is that the cashier at the supermarket is flummoxed when my bill comes to $90.25 and I hand then $100 bill and a quarter. They don't know what to do. Thinking deeply about 3rd year math majors is NOT the place to start solving this deficiency.
And this:
Imagine 4th graders being taught why time slows down for people who move relative to us.
Why THE HELL is anyone considering teaching Einstein's Theory of Relativity to 4th graders. This -- THIS -- is why 9-year-olds decide that they cannot ever understand math.
At the supermarket near my home the cashiers are only allowed to give you the change that the cash register displays. What you did would upset the entire space-time continuum. Those young dummies can’t reason beyond their “training”. Now if you want people that can think and handle change, truck stop waitresses and cashiers have got it down to a science.
I thought the same thing when our kids were being taught imaginary numbers in sixth grade. What good is that? I am quite sure that the teacher didn’t understand it.