What you are teaching them is that you care more about the grade than your child. Who goes around checking averages for thei children’s grades? Is there so little going on in your life that you have to live through your children? It seems to me that threatening to go to the school board over a .1% difference ( what you call rounding) is a waste of the school board’s time and effort. You mention that it is math and science that she is getting lower grades in, have you ever considered that she just is not doing the work the way the teacher has asked for it to be done? I still remember a college thermodynamics class where the prof insisted that you fold the paper a certain way, put your name in the upper right hand corner, and an answer column down the left margin. If you did not do it that way you got ZERO for the assignment (even if it was the final exam). I only had to screw that up on one quiz before I became compliant....lesson learned