It should really be about what's best for the child. It's a shame when it's not.
Grinnity would say go and talk to them about how this makes your child feel. Tell them what she's telling you. Tell them what it's doing to her self esteem. This gets through better than talking about research or excellent abilities because it's no longer about theories or about what you or I think but about what it's clearly doing right now to the emotional development of your child.
This is exactly what I did. I told them (the vice principal was there; this was the teacher's idea) she was very unhappy and was crying about math class. Looking back on it, they didn't really react to that at all. DD herself asked for harder work, but again, nothing.
In the teacher's eyes, DD isn't the best student in the class. She ignored everything I showed her at the beginning of the year and was talking about "mastery," and that DD doesn't get 100% on every test she takes. She never gets less than 80% (often 90%+). I told her that a) >80% consistently says she knows the stuff. I also tried to explain that her mind works very quickly and that she needs harder work that will force her to slow down. She's used to being able to race through most things, and isn't learning how to
slow down and think or how to confront a challenging problem. The teacher backed away from the word
mastery but nothing else I said seemed to take hold. Everything went back to this stuff about word problems that I just haven't observed, and there seems to be no concept that an 8-year-old could be doing 5th or higher grade math. As I mentioned, it's as though you don't know 4th grade math unless you've done the entire course
in their book.
I'm afterschooling her and it's helping, but I'm not happy about wasting her time in math class. This is just wrong. Teaching her is the school's
job, after all. I've never understood why this stuff has to be so hard.
