My son using Math Rocks. Like previously stated, children qualify in 2nd going into 3rd, 3rd going into 4th, 4th going into 5th, or 5th going into 6th. It is solely based upon the average of winter and spring MAP scores. Depending upon what grade your child is currently in depends upon how many standard deviations higher than their peers their average must be. There is no set number since it varies year to year per the peer group.
We are very happy with the program. Our son loves the program and his Math Rocks teacher.
I don't know that it is possible to say the text is a particular book. Often he is working on things not in a text, the homework that comes home tends to be more work that the teacher seemed to create her own work. I have seen 2-3 different books come home as well.
