I don't find it unreasonable for a smart first grader, or even kindergartner. I'm unsure whether it is doable for a typical one. I based my earlier response on

I don't find it unreasonable for a smart first grader, or even kindergartner. I'm unsure whether it is doable for a typical one. I based my earlier response on what I knew from others as children. But, seeing your response and those of others in this thread, perhaps I was mistaken. Then again: >American parents and teachers are doing an unexpectedly bad job of teaching it. I can't speak for American parents but American teachers aren't so good in general.