Rounding can be challenging the way they teach it these days. My DD, who is pretty high ability in math, has been tripped up by it more than once. It's not the way you might think of it, or at least it wasn't for me. That said, if she is 99th% and they are only teaching one grade up, you aren't going to be happy. Curricula are in flux, though. DD's math (one grade up--she is in a high ability program) has been all over the place in terms of difficulty, IMO, but they keep switching textbooks. 3rd grade (really 4th) was poorly edited and sometimes too hard, 4th grade (really 5th, and a diff curriculum) was much too easy, and now 5th grade (new book AGAIN) appears to be surprisingly hard, coming from last year's basis. I don't know if this is somehow related to Common Core, but I see CC objectives listed on her work.
