The challenge is to find a model that will address these obstacles AND teach them math at a rapid enough rate that they can "catch up" with their peers and ready themselves for the real world in time for graduation. Is that possible? I would suggest not, and I speak from experience. The bottom line: you do NOT have to identify the source of the deficiency if you can get them to "buy in" to a program that addresses the mathematics in such a way that they will do enough to see success.
This is what we began doing at Edina (MN) High School in 2008. The program we developed is eMath (www.edinamath.info/) and test scores suggest that it is working. Traditional textbook-driven math courses are hopelessly flawed in two major respects:
1) The assume that all kids in class are in the same place at the same time, and
2) The assume that all kids in class are able to learn at the same rate.
Because of these to flawed assumptions, a textbook model will not work for these kids. It will take a model that allows kids to begin where they are and move at the rate that accommodates them in order to make progress. eMath does that with the help of Plato Learning. View the eMath website for details.
Let me know what you think? Thanks for reading.