One of my personal teaching goals has been to incorporate more student centered and exploratory learning to my lessons. There are a lot of these lessons available for free on the internet. The problem with this approach is that they do not follow a single theme, strategy, or approach to learning. This results in confusion for the students as they have to adapt to new styles, notations, expectations, etc. Much of the time learning focuses on learning each lessons nuances than the activity itself. My department has also been looking at the Core Plus and Interactive Mathematics Program. So far, both these programs seem to fit my students needs and my goals, but implementing a new curriculum is costly and requires approval from many parties.
The solution may be in EngageNY. This is a curriculum put forth to meet the common core standards for the state of NY which features student based explorations and multiple representations. I have used a few of these modules in my classroom with a lot of success. Many of these modules meet my courses scope and sequence requirements. Yet, the lessons create a broader understanding of concepts than my current curriculum affords. Also, its free for use. So far the only drawbacks I have found include: not enough kinesthetic learning opportunities, lack of support materials for extra practice or absent students, assessments that are publicly posted, and large amounts of material that need to be printed for student use.
This spring I plan on replacing my trigonometry units with the modules from the EngageNY curriculum. I will post my results in May concerning this.