A minor update:
Despite the agreement that the third and fourth grade teachers would make appointments to meet with our educational consultant to plan and implement, no appointments were made. DS7 took the end-of-fourth math test and scored 100%, but he has not yet been scheduled to take the end-of-fifth math test yet. NECAPs were taken by DS7, but results will apparently not be in until February 2013, and DS7 hasn't been given the fall math MAP test.
I and my wife sent an email asking about the status of the "math menu" (a group of choices for DS to choose whatever learning activity strikes his fancy) and the other outstanding items. We also asked that he be excused from all third-grade math fact drills (granted in an email response afterward), be excused from fourth-grade math homework to free up time for afterschooling instruction (granted), and that he be free to bring work from home to do during math class (not granted, though his teachers did agree that he could bring work to do during bits of math time in his third grade class). I think, regarding the last request, that the teachers are still reluctant to look like they are throwing in the towel. DS is stuck in class twiddling digits while the class learns about multiplication, place value and averages.
We also asked that one menu item be hard-coded to always represent a math lesson next in his curriculum, whatever that turns out to be, but that request was completely ignored. Our math consultant is now of the opinion that afterschooling/partial homeschooling and sending work to school is the best approach, and also doesn't think that the rest of the work in the third grade class is at his proper level either, though she hasn't been allowed to sit in on any classes yet.
For now DS7 is excited about learning algebra from the book Val mentioned, and I also highly recommend it after having had a chance to go through it. Eventually we plan to do Age of Problem Solving, but for now he is loving this book. When he hits a new topic in passing he always has to know more, so we just do an ad-hoc mini-lesson and move on. For instance, early on there was this question:
For each variable find a value that will make a true statement. If possible, find more than one value...
(b � b) + 3 = 4b
He found the answer quickly, I suspect by the numbers just popping into his head, and couldn't easily verbalize how he'd done it. That prompted a short first lesson on factoring polynomials, which he loved, even though it doesn't first appear until a bit later in the book.
Thus there've been some improvements, but he continues to have his time pretty much wasted in school. His first "book report" was to read a biography-- cool, right? He chose "Maus", read it twice and loved it. However, the report itself turned out to be to write ten sentences about the biographee on strips of paper, then put the strips inside a coffee can decorated to look like the person. Math class time is wasted until further notice. He advances in reading on his own time as well.
