he can do lessons in the 4th grade math book during that unit. GREAT! But- the school uses Envision Math Curriculum and most of the 4th grade lessons are extensions of the same concept. For example, Subtraction w/ three digits to 5+ digits.
This is exactly what my DS told me about the Envision math. So, he gets pulled out for "differentiated math instruction group" twice a week now but he has expressed disappointment in it b/c of this very reason. He says the good thing is they get to do "games" or something once they master their lesson ( I think they are math games or logic games), whereas before in regular class they were suppose to just sit there or do the same thing over and over and over. I have no advice for you unfortunately but am interested to hear what other's advise. Envision Math sure is turning out to be quite a dud of curriculum!