How old are they?

When I was a kid, our 1-6 grades were letters (E, G, S, N) that generally corresponded to "above, at, below, well below expectations" The point was to detect what needed extra attention and to help guide focus of the parents and teachers. 30 years later my kids have the same thing but the labels are a bit different. Grades 7-8 introduce A-F and then high school is just percentages.

I've also seen the opposite in a relative's reaction to their kid getting number grades. They fixated far too much 3 or 4 points either way and not the general signal.