Maybe you can somehow angle this in a way that makes the school know that your son already knew about and was excited about the upcoming algebra, and was extremely disappointed when he found out that he might not now get what he was told he was getting.
And also tell her you asked the algebra question to your DS, and he got it right. That some number of 8th graders got it wrong has no effect on a child who is not performing as an average child; he is beyond that.
Since the principal seems to like articles, I am sure you can find some good ones to send her. Anyone here have a suggestion? Maybe you can find something on hoagies:
http://www.hoagiesgifted.org/math_gifted.htmAlso, maybe you can mention something about spiraling curriculum, and that your DS doesn't need as many repetitions as other kids, and that he'll be fine with the review that comes in the beginning of the 5th grade math.
