This study aims to determine the increase in activity and achievement in learning mathematics for class VIII H students of SMP Negeri 2 Tabanan in the 2022/2023 academic year after implementing STAD type cooperative learning. This research is a classroom action research. The research was designed to follow the stages of initial reflection, cycle I and cycle II. The subjects of this study were 35 students of class VIII H of SMP Negeri 2 Tabanan. The method used in data collection is descriptive analysis method. As for the results of data analysis in cycle I, the average score of student learning activity was 2.30 and the average score of student achievement was 67.29. In cycle II, the average score of student learning activity was 3.30 and the average score of student achievement was 74.71. From the analysis of student learning activity data in cycle I and cycle II, an increase of 1.00 or 43.49% was obtained. From the analysis of student achievement data in cycle I and cycle II, an increase of 7.42 or 11.03% was obtained. The results showed that the application of the Student Teams Achievement Divisions (STAD) cooperative learning model could increase the activity and learning achievement of mathematics students in class VIII H, SMP Negeri 2 Tabanan, academic year 2022/2023.
