I don't pay much attention to grades right now. My twins are in first. One of my DS's received a "low proficient" rating on a common core standard recently because he obviously wasn't paying attention for one sheet out of six that he had to complete that week. That one sheet had several incorrect answers that were obvious inattention mistakes (as in his work showed the right answer, but he marked the wrong one on multiple choice), but he got everything on the other five sheets right. At home he is doing much harder math- I guess he was just thinking about something else.