>>521142334 (OP)
it's what happens when you make fucking retards who do not understand any of what the subjects into teachers.
the kid's answer is just fine. the idea was to teach retards who cannot figure it out by themselves how to do estimations, so one answer could have been "a bit more than 200".
the kid just completed that mental step twice and narrowed it down even further, to somewhere between 225 and 250
but the teacher themselves is retarded as shit and does not understand the purpose behind this exam question they bought from somewhere.
you can see it with a lot of common core shit. if you have an alright feeling for math, you can usually tell what the original idea was, and see that it was supposed to teach those bad at math how someone who understands it instinctively would approach the problem.
but then it gets lost on the way because the people who teach it fucking suck at math.
my flatmate back during my studies who studies to become a teacher had mental breakdowns every exam season, and then when I looked at her training questions it was piss easy shit everyone should have already known from HS.