alt Hacker NewsI was actually bumped to ninth grade math from seventh grade, so I would have been twelve.
ETA:
Should add that this carried on through high school, and since I finished my math two years early, I took college-level courses for math the last two years.
I missed 3 months of 4th grade. When I came back, the teacher told my mom that I could not continue, because I'd missed 3 months of education. I'd have to finish out the year in 3rd grade.
My mom would have none of that, and demanded I be put back in 4th grade.
And so I was, and it was like I wasn't gone for a single day. The class had not advanced at all.
This was quite unlike university, where I didn't dare miss a single lecture.