I�m so sorry that you are not finding an ally in your son�s principle.
It took us several years before our school took action to accommodate our son in math. It was the exact same situation! He was already one year ahead of where he would have been based on age, but was extraordinarily bored with grade level Saxon math. I wish I could tell you that it (Saxon math) will accelerate, but I can�t.
I got my copy of �Developing Math Talent� yesterday per your recommendation (thanks). I haven�t gotten too deep into it yet, but I can see it will be very helpful in interpreting my son�s Explore results. I think I will order a second copy for the school.
According to the authors (and experts in the field), enrichment and critical thinking exercises are not a solution for children who are gifted in math although they may compliment an advanced academic curriculum. The advanced instruction is critical to nurture the aptitude and interest.
I know you want this addressed now. Maybe you will have to prove to them that you are right about his abilities. For now, keep up the supplemental instruction along with the fight.
I bet it made a positive impression on your son to know that his parents are lobbying for him. Both our kids witnessed my husband and I insist to be heard during a school board meeting. My husband read the well researched letter that we had sent to each school board member (nobody responded) in front of a rather intolerant crowd. They essentially blew us off, but my kids saw us try (and fail) on their behalf. They also see that we eventually got their situations resolved (for the most part). These are good lessons.
Keep trying. I am also praying for your family.
Diana