Cost is a huge factor. Asking a student to write what 7+8 is on a sheet of paper is a cheap substitute of high quality math education.
Not saying that this is the case in OP, it's very likely that the teacher will eventually catch up to the fact that a kid with A on their homework isn't quite a math genius. The same systems that would catch a child being aided by parents or cheating would catch this anomaly.
Not saying that this is the case in OP, it's very likely that the teacher will eventually catch up to the fact that a kid with A on their homework isn't quite a math genius. The same systems that would catch a child being aided by parents or cheating would catch this anomaly.
Teachers are a well trained profession after all.