So the years don't really matter when the kids are accelerated.
They will top out of everything, even the distance education and concurrent enrollment options.
Some high schools have no problem if they continue their education at a local college. Some do...If the classes aren't "articulated" with the high school, they may not receive high school credit for the college classes. Crazy! But it happened to us. (I figured out a loop hole if someone is stuck in this position.)
Typically, the gifted kids top out of their subjects, move on to college classes (taught by semester basis) and move through a college program. Once they start taking college classes, their time/years requirement changes.
A college course taught by semester is equal to a year of high school or more. So they really don't need 4 years of Eng/Math/Sci/Hist, but 4 high school credits of Eng/Math/Sci/Hist.
This adds some flexibility when earning their AA or more, because they need to take other college courses, such as foreign languages, statistics, health, and humanities.
Also, be aware...that some colleges will try to get the high school kids to take only science classes "for non-science majors." Sometimes the lab is optional in these, sometimes not.
If your kids don't have a strong science interest or background, these are fine for a starting point, but not the same depth as the regular science for science majors which always requires a lab. Depending on their major, they will need to then take "the science for science majors" courses. Sometimes this is a viable option, if they have a heavy load and want an introduction to physics, before taking the fast paced one, for example. Also, you want A's for scholarships and grad/law/medical/dental school. It is smart to play it safe, if needed.
Also, if they take only one semester of science for science majors at the high school's feeder college, they will have have to retake it before they take the second semester at their final university. These intro/weeder courses need to be taught combined at one school (Bio 1A/1B, Chem 101/102, Physics, etc)...the universities teach them together and juggle topics. so it's not good to come in half way.
And that's just Science...LOL
(I hope this all makes sense...and helps!
)
Some day I'll write a short post!