<![CDATA[ABSTRACT This study aims to improve the mathematics learning outcomes of fourth grade students at SDN 1 Sukorejo by applying the Problem Based Learning (PBL) model with the help of concrete media. The research method used was classroom action research consisting of two cycles. Each cycle includes the stages of planning, implementing, observing, and reflecting. Concrete media is used to visualize the concept of geometric shapes in learning. Learning outcomes data obtained through tests, observations, and interviews. The results showed that there was a significant increase in student learning outcomes after implementing the PBL model assisted by concrete media. In the first cycle, 8 out of 13 students completed the Minimum Completeness Criteria (KKM), while in the second cycle, 12 out of 13 students completed the KKM. In addition, students also reported that the use of concrete media helped them understand concepts better because they could see 3D shapes. This study concludes that the PBL model assisted by concrete media is effective in improving the mathematics learning outcomes of fourth grade students. Keywords: learning outcomes, PBL models, concrete media ABSTRAK Penelitian ini bertujuan untuk meningkatkan hasil belajar matematika siswa kelas IV di SDN 1 Sukorejo dengan menerapkan model Problem Based Learning (PBL) berbantuan media konkret. Metode penelitian yang digunakan adalah penelitian tindakan kelas yang terdiri dari dua siklus. Setiap siklus meliputi tahap perencanaan, pelaksanaan, observasi, dan refleksi. Media konkret digunakan untuk memvisualisasikan konsep geometri bangun ruang dalam pembelajaran. Data hasil belajar diperoleh melalui tes, observasi, dan wawancara. Hasil penelitian menunjukkan adanya peningkatan yang signifikan dalam hasil belajar siswa setelah menerapkan model PBL berbantuan media konkret. Pada siklus pertama, 8 dari 13 siswa tuntas Kriteria Ketuntasan Minimal (KKM), sedangkan pada siklus kedua, 12 dari 13 siswa tuntas KKM. Selain itu, siswa juga melaporkan bahwa penggunaan media konkret membantu mereka memahami konsep dengan lebih baik karena mereka dapat melihat bangun ruang secara 3D. Penelitian ini menyimpulkan bahwa model PBL berbantuan media konkret efektif dalam meningkatkan hasil belajar matematika siswa kelas IV. Kata Kunci: hasil belajar, model PBL, media konkret]]>
