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
Hello,
Thank you for your comment. That’s one of our main threads, “On the sensitive topic of being a Harry Potter fan while acknowledging JKR’s transphobia” https://discuss.tchncs.de/post/9633657, quoting https://www.popsugar.co.uk/entertainment/harry-potter-fans-jk-rowling-transphobia-essay-49214964
Link to the research paper: https://link.springer.com/article/10.1007/s10583-021-09446-9
Plot twist: jk is a selfhating queer and her subconsciousness wrote Harry Potter to break free without disappointing her self hating parents.