Yes, we've run into this before in math; the rigid adherence to "protocol" dictated by the pedagogy happening within the confines of the course content.
On the one hand, it IS important that students master the skills that they are being taught-- as they are presented-- on the other, it's not appropriate to continue drilling students on what they genuinely have total mastery of already.
I'm going to guess, here, that your math instruction is using a common curriculum such as EveryDay Math or EnVision or something like it-- and they are a spiraling, incoherent MESS, to be kind.
I'm further going to guess that your math program is aimed at meeting common core standards, and that there is mild to moderate panic about this on the part of administrators and teachers.
So knowing that, what would I do in your shoes? Find a tactful way of having them decide to test your child regarding mastery of the year's (or maybe even years') learning objectives, and see where he SHOULD be placed.
