<![CDATA[Low mathematics learning outcomes remain a common problem at the junior high school level, including at SMP Negeri 3 Sungai Pua. Mathematics Midterm Examination scores for seventh-grade students in the 2025/2026 academic year showed that only 14 of 91 students achieved the Minimum Mastery Criteria (KKM), while 77 students did not. This study aims to determine the effect of the Student Teams Achievement Division (STAD) cooperative learning model on the mathematics learning outcomes of seventh-grade students at SMP Negeri 3 Sungai Pua. This study employed a quantitative approach with an experimental method, specifically a pre-experimental design. Class VII.1 served as the experimental class (21 students) and received instruction using the STAD model, while Class VII.2 served as the control class (22 students) and was taught using a conventional learning model. Data were collected through an essay-based mathematics achievement test that had been tested for validity, reliability, difficulty level, and discrimination power. Data analysis used the Liliefors normality test, homogeneity test, and t-test at a 5% significance level. The results showed that the mean learning outcome of the experimental class was 66.714, while that of the control class was 54.727. The t-test resulted in a calculated t-value of 2.84 and a critical t-value of 2.019, indicating that t_calculated > t_table, so H0 was rejected and H1 was accepted. It can be concluded that the STAD cooperative learning model had a significant effect on the mathematics learning outcomes of seventh-grade students at SMP Negeri 3 Sungai Pua in the 2025/2026 academic year.]]>
