He was abducted by Hagrid when he turned 11 so that would place him maybe around the fifth or sixth grade.
I don’t know if canonically there are math classes at Hogwarts.
The thought came to while I was watching the anime Mashle. If you are into Harry Potter and One-Punch Man I’d recommend giving it a watch.
Someone mentioned this community below; I wanted to highlight it.
Small promotion for !harrypotter@literature.cafe
To be fair, I suspect the average adult in real life probably only remembers, and uses, 5th grade math.
Facts
Source: self
I bet I couldn’t help a 5th grader with their math homework.
Most people couldn’t, but that’s mostly to do with the way math is taught differently… (“New math” is better, fight me!)
can you add fractions?