Grades Around the World

[Famous Mortimer]

I seem to recall using the 93-100 = A system when I was in elementary school and then switching to factors of 10 in middle school and high school. I think maybe it has something to do with conditioning young children to accept arbitrary rules. I think cursive is the same way. They teach little kids to write weird and use this arbitrary grading system, then as soon as they've learned to accept it, they go "actually we're just going to use common sense now, write how it's easiest and use round numbers"