I promised I'd get back to this and here is my take. Remember, I am only talking from a math teacher perspective. With "common core" the first thing that I notice is the powers that be (some democrats and some republicans) are trying to back up the standards and make classes more "rigorous." By this I mean that 7 graders will essentially take a Pre-algebra course now and 8th graders will take an Algebra I course. Not a bad idea on the surface but this will lead to many problems in many schools because they expect EVERY KID to be able to do this and be successful, BUT they make no provisions monetarily or otherwise for the districts (at least in OK) when these kids do not perform up to par. They seem to expect the kids just to move on to the next level no matter what they might have missed and do exceptional work because they (congress) has deemed they be taught using tougher standards.
Also, the gap in just leaping things ahead a full year would more logically be filled by starting these new standards in early elementary and stepping up each year. For example, starting the CC standards in 1st grade one year and then moving to first and second grade, then to first, second and third grade, etc. They might even start at 3rd or 4th grade. I realize that takes time but to expect some of these kids (not all...in fact most can do it) just to magically make the jump over things they might have missed (remember I am talking from a math perspective) is ridiculous...and again, no provision is made for these kids, again, at least in Oklahoma.
Also, with the standards being moved back we are going to have to train more elementary math specialists. I can tell you that most generic elementary teachers are not qualified to teach the standards the powers that be are trying to implement in upper elementary (4th - 6th grades). Many simply do not have the math background to do it. Which brings up another point. We cannot even get enough math teachers to fill current teaching positions that are vacant. What makes them think they can leave pay and incentives at the current levels and be able to fill the positions of elementary math specialists that are sure to be created with the implementation of CC. It ain't happening.
Now to Mott's sample problem. He gives a good algebraic explanation to it in post #18, but I still would have to count off because he didn't use key vocabulary words like "sum" and "difference" and "product" or even "distributive property." According to our standards, correct vocabulary usage in the explanation counts for up to 20% of grading. Now tell me, what is more important on the job; to be able to do a problem or to be able to write a paragraph about how you do a problem? I think Bill O'Reilly might be great at common core because he is one of the greatest bloviators that I know.
I have more but this is all I have time for right now. I haven't even touched on limited English learners and how this it going to dramatically affect their math performance, or at least their grade. This is a group of learners who already become frustrated with Math. Or on the grades that schools will receive as a result of this CC curriculum. I see it, at least in Oklahoma, as a means of closing the doors on schools. Fine and dandy, but how are they going to solve the bussing problems created by this? Some want to make it as a bludgeon with which public schools can be beaten to death thus paving the way for charter schools. I am not willing to go that far but will conclude that I think CC has good points (more rigor, higher standards, etc.) and bad points, obviously. But a bunch of bureaucrats trying to implement these changes have no clue what they are doing and how to go about it.