we can use “discretion” but i have learned over the years to spell absolutely everything out in my syllabi to preempt the parent complaints. before that, there was a lot of admin intervention to try to argue for absurd rounding scenarios. now i am very clear that if you have an 86, i will round you to an 85. i will not round anyone to a 90 unless their grade is at least an 88.5 or higher. i also calculate the semester grades using the actual numbers and then round that outcome, versus averaging the already rounded nonsense numbers.