AbstrakPenelitian ini merupakan penelitian dan pengembangan yang bertujuan menghasilkan produk perangkat pembelajaran matematika dengan pendekatan saintifik. Penelitian dilakukan di MTs Negeri 1 Bolaang Mongtondow Timur. Pada penelitian ini model yang dikembangkan adalah pengembangan Four-D yang mencakup 4 (empat) tahap, yaitu: (1) pendefinisian, (2) perancangan, (3) pengembangan, dan (4) penyebaran. Uji pengembangan produk hanya dilakukan pada materi persamaan dan pertidaksamaan linear satu vaiabel. Hasil penelitian menunjukkan bahwa produk yang telah dilakukan uji pengembangannya telah memenuhi kriteria antara lain, valid, praktis, dan efektif. Hasil uji pengembangan yang memenuhi kriteria valid berdasarkan persentase penilaian ahli yang mencapai 100%. Dalam penelitian ini output yang memenuhi kriteria praktis berdasarkan penilaian guru dan siswa adalah kategori sangat baik, serta berdasarkan hasil observasi keterlaksanaan pembelajaran. Produk memenuhi kriteria efektif berdasarkan hasil belajar siswa pada kompetensi sikap, pengetahuan, dan keterampilan. Persentase siswa yang mencapai kriteria ketuntasan minimal (KKM) untuk kompetensi sikap, pengetahuan, dan keterampilan melebihi 78%.Kata kunci: pembelajaran matematika, pendekatan saintifik AbstractThis study was a research and development which aimed to producing mathematics learning sets with a scientific approach. This study was conducted at Public MTs 1 of East Bolaang Mongtondow. The developed model in this study was the development of Four-D which includes 4 (four) stages, namely: (1) defining, (2) designing, (3) development, and (4) dissemination. Product development tests are only carried out on equation and inequation of linear material of single variable. The results of this study show that the products that have been tested for development have met the criteria, among others, are valid, practical, and effective. Development test results that meet valid criteria are based on the percentage of expert evaluations that reach 100%. In this study, the output that meets the practical criteria based on teacher and student assessment was a very good category, and based on the results of observations of the learning’s implementation. The products which are meet the effective criteria based on the student learning outcomes in competency attitudes, knowledge, and skills. The percentage of students who achieved the minimum completeness criteria (KKM) for competency attitudes, knowledge, and skills exceeded to 78%.Keywords: mathematical learning sets, scientific approach