Yes, the principal suggested the skip, and he has said in no uncertain terms that DS' math talent needs to be nurtured. The school psychologist has recommended against the skip, but for the subject acceleration.
With the principal in favor of the grade skip, I'm guessing you'll get it, and I wouldn't let the school psych's opinion worry me too much - but fwiw, I'm coming from a place of having not-so-great experiences with our local school psychs! Before your meeting, think through all of your reasons for wanting the skip, think through the reasons the psych will put up for not doing the skip, and rehearse what you will say in response (polite but firm responses). We've found in advocating for our ds that just standing firm when a school staff person is attempting to intimidate us or push a perspective we strongly disagree with often works. If you want the skip and run into a brick wall with the psych, I'd ask the school for an outside private eval with a different psych.
Good luck!
polarbear
