I was first introduced to Which One Doesn’t Belong (WODB) at a talk given by Dr. Skip Fennell at NCTM Regional. I was very impressed with the engaging discussion that WODB inspired among the participants of Dr. Fennell’s session. I also loved how the focus was not on the correct answer, but rather developing participants ability to explain their thinking and justify their answers. Unfortunately, I was unable to use WODB with my students after the conference, because the semester was over (except for final exams). However, ironically a couple of weeks after the conference at a meeting of our local Math Teachers’ Circle one of the participants shared WODB . The circle members (all math teachers) absolutely loved it! Now that the spring semester has started, I am looking forward to incorporating WODB into my classes. I think that it will fit well with IBL methods. More specifically, I plan on assigning WODB items to students and having them present their problem solving processes and answers to the class. I also think it would be beneficial to ask students (particularly my preservice teachers) to create their own WODB. I am looking forward to using WODB this semester and will be sure to follow up on the blog with how things go.