Good question, I have no idea. The reason I can't answer is in my school district we will only start compaction in math next year so I really don't have a lot of answers. Until this year when the junior high has started implementing common core. Before honors/advanced math students were more likely just to skip either 4th grade math and/or 7th grade math. Math did a lot of spiraling and 4th/5th grade math curriculum were really not that different.
amylou: Your compaction of classes sounds unusual. Everywhere I've seen it.. (including the AP description of classes) AP Calc AB is the first semester of Calculus in one year, AP Calc BC is two semesters in ONE year. When you take the Calc BC test.. you get an AB 'score'. At our school one doesn't take AB Calc one year, and then BC Calc the next. The entire first semester would be review that way. Are you planing on them taking the AP test this year? I assume you know what the curriculum is for your H.S.'s AP Calc BC class. That said, at our school the first few chapters of AP Calc BC class is included in honors pre-calc and since my son isn't honors if he takes BC next year he will have to do some summer study.
