We always had problems at my school keeping students that were good at math.
As soon as they discovered that they could attend Miami Dade College or FL international (both public schools) for a fraction of the cost, the transferred out, leaving us with the students that could not understand math.
I would always have students come to my office after the semester was over, asking me to change their grade.
I never said no. I would hand them a piece of paper and a calculator and have them total up their own grade.
I would ask them if they understood how to calculate percentages. Mostly, they did not. So I showed them.
Then I would ask "what is the percentage?"
56.4% they would say. "60% is passing" I would reply. They would then get up and leave quietly.
On maybe a couple of occasions I would find an error. If it was in their favor, I would raise the grade.
I taught there for 32 years. 64 semesters and 30 summer sessions.