IS brilliant. He’s not dead yet!
Is it like flash cards? Learning the fact families? If so, you probably just don’t remember back.
I think Senegoid is basically right.
Why should set theory be taught in elementary school. I learned set theory after I had a term of analytic geometry, a year of calculus, a term of advanced calculus, a term of differential equations, and a year of modern algebra (which included, if you are interested, Galois theory and the Wedderburn theorems on artinian rings–called rings with DCC). Then I had a course that talked about sets. By that time, I had sufficient motivation to understand what it was about.
In maybe fifth grade, my daughter had the following experience. Exercise: how many subsets does a 3 element set have. Express your answer as a power of 2. Her answer: 2^3. The teacher’s answer: 256. The class laughed at my daughter since she never made mistakes. Where did the teacher get her answer:
She had gotten the correct answer 8 and then raised 2 to that power. At least that is the only explanation I could figure out.
Yeah, you BETTER apologize; you screwed up the joke.*
Anyway, an example of New Math: 342 - 173 = 1[del]5[/del]69…
*Base 8 is just like Base 10, if you’re missing two fingers.