[Anecdote only; no further OT]
Advanced calculus in 9th grade? Crikes, I went to "one of the best High Schools in the country" per national rankings, and I didn't get Calc until 11th, and only then because I was a smarty-pants who had knocked out both basic Algebra and Geometry at a private school in 9th and when I moved to the highly-funded-and-acclaimed public school in 10th, I was taking Algebra/Trig with a class of juniors and ditto for Calc with a bunch of seniors when I was a year behind.
We could make those Texas Instruments TI-45s sing, baby!

[/end OT]