Penelitian ini bertujuan mendeskripsikan kemampuan pemecahan masalah matematis siswa pada materi operasi bilangan. jenis penelitian yang digunakan adalah penelitian deskriptif kualitatif. subjek penelitian terdiri dari 6 siswa kelas vii-2 yang dipilih dengan teknik purposive sampling. purposive sampling adalah teknik pengambilan sampel sumber data dengan pertimbangan tertentu. pemilihan subjek dilakukan peneliti dengan rekomendasi dari guru dan peneliti menetapkan kriteria pemilihan subjek yaitu siswa sudah mendapatkan pembelajaran operasi bilangan dan siswa menempati tingkat kemampuan pemecahan masalah matematis tinggi dan rendah. instrumen pengumpulan data yang digunakan instrumen utama peneliti dan instrumen penunjang pedoman wawancara dan dokumentasi. teknik analisis data yang digunakan yaitu mereduksi data, menyajikan data, dan menarik kesimpulan. uji keabsahan data yang digunakan uji credibility, uji transferability, uji dependability dan uji confirmability. hasil penelitian menunjukkan bahwa: kemampuan pemecahan masalah pada materi operasi bilangan (1) siswa yang memiliki kemampuan pemecahan masalah tinggi adalah siswa dapat menentukan dan memahami masalah, serta mengetahui rencana dan melaksanakan rencana yang digunakan untuk menyelesaiakan soal tersebut, siswa mampu memberikan kesimpulan dari setiap soal yang dikerjakan. (2) siswa yang memiliki kemampuan pemecahan masalah rendah belum mampu memenuhi setiap indikator pemecahan masalah matematis. siswa telah mengetahui masalah dari beberapa soal dan terdapat pula siswa yang tidak mampu menuliskan hal-hal yang ada pada soal, untuk soal yang dipahami, siswa menyelesaikan soal dengan benar dan untuk soal yang tidak dipahami siswa hanya menuliskan sebagian kecil dari apa yang seharusnya. kata kunci: kemampuan pemecahan masalah matematis, operasi bilangan

This research aimed to describe the students' mathematical problem-solving ability on number operation material. the type of research employed was descriptive qualitative research. the research subjects consisted of 6 students of class vii-2 wo were selected using a purposive sampling technique. the purposive sampling was a technique for sampling data sources with certain considerations. the subject selection was determined by considering the recommendations from the teacher and the criteria of the subjects, namely the students who had learned number operations and the students who had high and low levels of mathematical problem-solving ability. the data collection instruments used were the main instrument namely the researcher herself, and the supporting instruments namely the interview guideline and documentation. the data analysis technique used was reducing data, presenting data, and drawing conclusion. to test the validity of the data, credibility test, transferability, dependability test, and confirmability test were used. the results showed that problem-solving ability on number operation material: (1) the students who had high problem-solving ability were the students who were able to determineand understand the problems, as well as know the plan and implement the plan used to solve the questions, they were able to provide conclusion from each question done; and (2) the students who had low problem-solving ability were not able to fulfil every indicator of mathematical problem solving, the knew the problems of several questions and there were also of them who were unable to write things about the questions. for the questions that were understood, they were able to solve the problems correctly, and for the questions that were not understood, they only wrote a small part of what should be. keywords: mathematical problem-solving ability, number operastion