Username checks out. :)

Ya the arithmetic is easy. Building up the associated algebraic expression(s) though is certainly high school level where I’m from.

I wish I understood why math education is the way it is. I really have no idea. I suspect the problem’s complexities are both wide and deep

no one actually good at math is going to become a K-5 teacher, they’re gonna get paid, so it creates a doom loop where each new generation of primary school teachers get progressively shittier at math.

There's a reason why 3rd grade "teachers' edition" textbooks for math exist. It's because those teachers need an answer key for 100+200.

As for "good at math", it's hard to see how a teacher with a degree can fail at 3rd grade arithmetic.

i have literally witnessed students in a senior level discrete math class struggle with simple algebraic operations. they were on the math education track.