@TheGFG, @mathmom ok that makes sense.
Like our science curriculum, our math curriculum works a little differently in that our students take all the math streams every year up until grade 10, just at an increasing level of complexity. Grade 11 math is Functions and in grade 12 there are separate courses in Advanced Functions (Pre-Calculus), Calculus, and Data Management/Statistics. Grade 12 advanced functions is a prerequisite for grade 12 calculus.
Basically the way the school is running the AP program they are accelerating the curriculum 1 year so that they can do AP Calculus BC in 2nd semester of the senior year. AP Biology, Physics 1, and Chemistry can be done 1st or 2nd semester of senior year.