Maybe you got lucky then, because when I was a kid, rote memorization was the only way teachers would accept the answer. If you changed the problem to 10 + 6 or the one op posted, the teacher would tell you that you did it wrong. This is why I just decided to do this regrouping in my head and just write what the teacher wanted because I would get the right answer anyway and not get told it was wrong.
You are probably young then. Probably schooled post 2011 when common core started being implemented.
Hmm no I’m not
Maybe you got lucky then, because when I was a kid, rote memorization was the only way teachers would accept the answer. If you changed the problem to 10 + 6 or the one op posted, the teacher would tell you that you did it wrong. This is why I just decided to do this regrouping in my head and just write what the teacher wanted because I would get the right answer anyway and not get told it was wrong.