Mark writes: I will concede that Investigations may be a great program for an experienced "good math teacher." However, not all teachers experienced.... and not all teachers are good math teachers.
Mark, Isn't it sad that all teachers are not good math teachers? It seems that in the past (maybe still) there was a perception that it takes training and skill to teach a child to read. At the same time the perception was that anyone who can do arithmetic can teach it to our young children. After all, it only amounts to memorizing facts and algorithms.
The NCTM Standards, the work being done through the National Science Foundation (NSF), Investigations Math, and many other things are trying to change that. If we are going to turn out world class math students, they need world class curriculum and teachers. Unfortunately many elementary teachers are not strong in math, which is one of the reasons that NSF and the states are putting a lot of money into training teachers to teach beyond memorizing. The new emphasis on mathematical reasoning and problem solving is part of what makes Investigations look so different from elementary math a generation ago. But this new emphasis doesn't eliminate the need for learning basic facts and developing efficient computation procedures.
As others have said, curriculum is designed to support teachers. It can't and shouldn't be asked to replace them. More than anything else it is the quality of teaching that determines what is learned. If we are changing our expectations for students and teachers, and I believe we have radically done that in the last generation to try to be competetive internationally, then we need to be sure that teachers are prepared and supported as we make these changes.
My fourth grade students have soared using Investigations. They are so much stronger than the students I taught before Investigations was adopted in our district. Nancy