During our experiences as high school mathematics teachers, we have discovered these three things. First, many high school students do not like to take mathematics courses. These students sometimes find that mathematics is boring and believe that it will be of no use to them after they graduate from high school. Stuart (2000) states that many people think of mathematics as something that causes stress and is unpleasant. Such students have high anxiety about learning mathematics and trying to succeed. Second, students have difficulty expressing their thoughts on paper or in front of their mathematics class. This phenomenon may occur because many traditional mathematics classrooms foster a competitive atmosphere among students (Johnson and Johnson 1989). Third, the students are not accustomed to taking an active role in learning mathematics. In light of these discoveries, we wanted to find a method of teaching high school mathematics classes that would help our students understand and enjoy the mathematics. In particular, we asked the following question: Would our students understand and enjoy mathematics more if we tried a cooperative learning approach rather than the traditionally taught teacher-centered method?