Interesting. So it seems that from reading this, Canada, or at least Ontario, has a lot more electives at grade 12 than the US. So this might be more like the UK with their A-levels. In the US a highly motivated student might take say 4-5 AP courses, which would essentially count as their freshman year at university. But they would be unlikely (short of going to a few dedicate highschools) of having more than maybe 2 math courses in a single year.