Argh, that must be so annoying given that you carefully considered two choices and the offer of math acceleration was a factor in your decision! I think if it were me I'd be going in with both a smile and a sting - saying that of course you understand the importance of applying maths and of the various K skills, but that the principal will remember having agreed on [date] that [child] would be accelerated to 1st for maths and that this was a major factor in your decision to send him there. I'd copy to the other recipients of this email, so that they all knew the principal explicitly offered this - he may be feeling that he shouldn't have done, and wriggling.
I'd try to leave open, though, the possibility that there really *is* a better option for him than subject acceleration. It may be that the principal said yes because you were keen on it, but that the principal knows less about what will work in the school than these other people do and they may actually have better ideas. My angle: I was quite keen* for my mathy DS to go to a higher class for maths to start with, but in the end I'm glad I let them convince me that it wasn't sensible. In the early years classrooms here, at least, they don't have a fixed timetable that would make it practical to go out for one lesson and come back for something else - he'd perpetually have been coming back in the middle of something. (They have a timetable, but as it's all one teacher, it gets honoured in the breach.) I think that was a major reason why my DS's school weren't keen on the idea, but the effect of the differentiation he got (at school and supported at home) was that within months he was a lot more than one year ahead anyway, which made the whole thing moot. I think subject acceleration would have just left him bored slightly further on, and not solved the problem at all.
*ah, actually, we have archives to keep us honest :-) - seems my feelings
at the time were a bit more complicated than that!
