DS is only a 6th grader so behind your DS. As such, take my opinion with a grain of salt. However, we have considered some of the same issues and ultimately declined the opportunity for DS to take Algebra (instead of Pre-Algebra) back in 4th grade so now he will not take Calculus until 9th grade. We made that choice mostly because DS wanted to be confident of the strongest foundation and also because I wanted to delay Geometry until 7th grade due to misgivings about his relative visual-spatial weakness. As it turned out, the district switched the gifted math sequence (Geometry now before Algebra II) this year so DS ended up taking Geometry as a 6th grader anyhow. Even though Geometry has turned out to be very easyfor DS, on balance I am actually glad that we slowed him down. Since the acceleration decision at the beginning of 4th grade, we have discovered math competitions (AMC 8, AMC 10, etc.) and discrete math (Probability and Combinatorics as well as Number Theory). Based on the information that you provided, it appears that your DS may benefit more by challenging himself to improve in the area of competition math. I think that colleges, particularly selective ones, will be more favorably impressed by high AMC 10 and AMC 12 scores than Calculus in 9th grade or an 800 SAT Math. To echo several other posters, trigonometry is very important as a strong foundation for calculus as well as in competition math. I know that DS was lamenting a while back that he had trouble with a couple of competition math problems because the little bit of basic trigonometry(the 6 trig. functions plus common applications) that he briefly covered two years ago in Pre-Algebra was now fuzzy.
