Penelitian ini bertujuan untuk meningkatkan hasil belajar dan partisipasi aktif siswa kelas I SD Negeri Ketegan pada materi operasi penjumlahan melalui penerapan model pembelajaran kooperatif tipe Student Teams Achievement Division (STAD) yang diintegrasikan dengan media konkret PAPINKA (Papan Pintar Matematika). Penelitian ini menggunakan pendekatan Penelitian Tindakan Kelas (PTK) dengan model DDAER (Diagnosis, Design, Action and Observation, Evaluation, Reflection) yang dilaksanakan dalam dua siklus terhadap 19 siswa. Hasil penelitian menunjukkan bahwa pada Siklus I, dengan penerapan Problem-Based Learning tanpa media PAPINKA, tingkat ketuntasan belajar siswa baru mencapai 68,42%. Setelah dilakukan perbaikan tindakan pada Siklus II melalui penerapan model STAD berbantuan media PAPINKA, ketuntasan klasikal meningkat secara signifikan menjadi 89,47% dengan nilai rata-rata evaluasi 86,32, disertai peningkatan partisipasi aktif siswa dalam kegiatan pembelajaran. This study aims to improve the learning outcomes and active participation of first-grade students of Ketegan State Elementary School on the material of addition operations through the application of the Student Teams Achievement Division (STAD) cooperative learning model integrated with the concrete media PAPINKA (Mathematics Smart Board). This study uses a Classroom Action Research (CAR) approach with the DDAER model (Diagnosis, Design, Action and Observation, Evaluation, Reflection) which is implemented in two cycles on 19 students. The results of the study show that in Cycle I, with the application of Problem-Based Learning without PAPINKA media, the level of student learning completeness only reached 68.42%. After corrective actions were carried out in Cycle II through the application of the STAD model assisted by PAPINKA media, classical completeness increased significantly to 89.47% with an average evaluation value of 86.32, accompanied by an increase in student active participation in learning activities.