Abstract
In this study, we proposed a learning-centered DIY mathematics instruction for students to actively design instructions and developed important competencies. The research problems of this study were as follows. First, how did learning-centered DIY mathematics instruction affect math academic achievement? Second, how did learning-centered DIY mathematics instruction affect the affective domain? Third, what was the reaction of students to the implementation of the learning-centered DIY mathematics instruction? For this purpose, this study was conducted with 58 students in 2 classes of 2nd grade of 00 High School located in 00 Metropolitan City. As a result of the study, first, it could be seen that the study group that taught the learning-centered DIY mathematics instruction was very helpful in the change of mathematics academic achievement compared to the comparative group who taught the explanatory instruction based on traditional textbooks. Second, the research group showed a significant improvement in the affective domain compared to the comparison group. Third, the responses of the students in the research group through the learning-centered DIY mathematics instruction improved in a positive direction, and there were some negative responses.