After spending about 15 minutes navigating your website and partaking in the activities I would have to say that I enjoyed what you have created. Using pizza is a common idea that teachers use in their classrooms, so transitioning from a traditional lesson to this site would be seamless. I also believe that this site would be a tremendous resource for my remidial students who could use a "brush-up" on their basic fraction skills. Using this site in conjunction with traditional methods would certainly enhance lessons for my students currently enrolled in AIS services.
The only concern I have is the ease with which the site is navigated. I myself find it easier when links to the table of contents, next activity, etc. vary in appearence from the remainder of the site (ex. using tabs as links). Other than that... excellent site!!!