My guess is that the other class is all high reading with 1/2 high ability in math (approximately)....but the only way to find out for sure is to ask. Is this third grade? You may find out that if she switches classes, the math in the other class is even worse. Is there another parent you can ask about what they are doing in math?
Rounding can be a 4th or 5th grade skill--I think it depends on the place value. Rounding to the nearest 10 for two weeks would be a lot easier than if it's all mixed up with hundreds, thousands, hundred-thousands, etc. (still really easy, though-- my kids both understood it in minutes).
DD is going into a class with all gifted kids, and here I hear the opposite, where if a kid misses even a day they can fall behind. They supposedly go super fast and accelerate through all that basic stuff. So I'm not nervous it will be too easy, I'm nervous it will be too hard. We shall see.
