ABSTRAK Telah dilakukan penelitian mengenai Penggunaan Model Pembelajaran Problem Based Learning untuk meningkatkan hasil bejajar Matematika Materi Bidang Datar di SD Negeri Sitanggal 02. Penelitian dengan menggunakan PTK model Hopkins dengan menggunakan model pembelajaran Problem Based Learning (PBL) dengan berbantu media pembelajaran matematika serta penerapan metode demontrasi. Hasilnya setelah dilakukan penelitian selama dua siklus 96% siswa tuntas dengan rata rata klasikal 75, swedngkan keaktifan siswa menunjukan trend semakin tinggi dari mulai pra PTK sampai siklus 2. Dari hasil penelitian ini dapat disimpulkan bahwa model PBL berhasil dalam Pembelajaran matematika dan bisa menuntaskan capaian pembelajaran pada materi bidang datar di SD Neegri Sitanggal 02. Kata kunci: PBL, Matematika Bidang Datar, PTK. THE USE OF THE PROBLEM-BASED LEARNING MODEL TO IMPROVE MATHEMATICS LEARNING OUTCOMES OF FLAT FIELD MATERIAL IN SD NEGERI SIDATED 02 ABSTRACT Research has been carried out regarding the use of the Problem Based Learning Model to improve Mathematics learning outcomes on Flat Field Material at the Siangkat 02 Public Elementary School. The research used the Hopkins model PTK using the Problem Based Learning (PBL) learning model with the help of mathematics learning media and the application of the demonstration method. The results after conducting research for two cycles were 96% of students completed with a classical average of 75, while student activity showed an increasingly higher trend from pre-PTK to cycle 2. From the results of this research it can be concluded that the PBL model is successful in learning mathematics and can complete learning outcomes on flat plane material at Neegri Si Date 02 Elementary School. Keywords: PBL, Flat Field Mathematics, PTK.