I taught mathematics using traditional texts for 19 years before I saw a sample of CPM. It was the curriculum I had been looking for. Many in my department were frustrated with the lack of problem solving ability of our students at all levels of math using traditional books, especially with our upper level pre-calculus and calculus students. While they could manipulate the problems well enough, they did not understand the underlying concepts and could not solve many basic applications. CPM has changed all of that while reenergizing the teachers. Most of the lessons are designed with problem solving as a central part of them. Student math confidence has increased. The number of students at all levels of mathematics in the high school has increased while failure rates have decreased. Students develop the ability to think through problems. After the first year of implementation, our testing coordinator said to me that students were no longer just guessing on questions they were not sure of but actually taking extra time to reason their way through them. That first year our state test scores jumped 14% and have increased every year from 2005-2009.
A secondary benefit of the Connections series is that it makes the math accessible to all students, which allowed us to eliminate our pre-algebra course. All incoming students start with the Algebra Connections course or higher. We have also been able to eliminate our multiple level courses. Before CPM we needed three courses for Geometry and two for Algebra 2. We now just have one at every level and have reduced failure rates at all levels.