Penelitian ini bertujuan untuk meningkatkan kemampuan representasi matematika siswa melalui model pembelajaran core (connecting, organizing, reflecting, extending). penelitian ini dilaksanakan di smp negeri 5 tarakan pada semester ganjil tahun ajaran 2019/2020 pada kelas viii. jenis penelitian ini adalah penelitian tindakan kelas (classroom action research). subjek penelitian adalah siswa kelas viii-5 smp negeri 5 tarakan tahun ajaran 2019/2020 yang berjumlah 32 siswa, terdiri dari 14 orang perempuan dan 18 orang laki-laki. teknik pengumpulan data dalam penelitian ini menggunakan instrumen tes kemampuan representasi matematika siswa. teknik analisis data yang digunakan adalah analisis data keterlaksanaan pembelajaran guru dan hasil tes kemampuan representasi matematika siswa. penelitian ini dilaksanan dalam 2 siklus, yang terdiri dari 3 pertemuan pada setiap siklus. hasil penelitian ini menunjukkan bahawa kemampuan representasi matematika siswa pada siklus i sebesar 68,75% siswa berada pada kategori minimal baik dan siklus ii mengalami peningkatan menjadi 93,75% siswa berada pada kategori minimal baik. berdasarkan hasil penelitian di atas dapat disimpulkan bahwa model pembelajaran core (connecting, organizing, reflecting, extending) dapat meningkatkan kemampuan representasi matematika siswa pada materi persamaan linear dua variabel pada kelas viii-5 smp negeri 5 tarakan. kata kunci: kemampuan representasi matematika, model pembelajaran core (connecting, organizing, reflecting, extending)

This research aimed to improve the students' mathematical representation ability through the core (connecting, organizing, reflecting, and extending) learning model. this research was conducted at grade viii of smp negeri 5 tarakan in the odd semester of the academic year 2019/2020. this research was classified into classroom action research. the rescarch subjects were 32 grade viii-5 students of smp negeri 5 tarakan in the academic year of2019/2020 consisting of 14 female and 18 male students. the research data were collected using the students' mathematical representation ability test instruments. the collected data were then analyzed using the teachers' teaching-learning implementation and students' mathematical representation ability test results. this research was conducted in 2 cycles consisting of3 meetings in each cycle. the research results showed that the students' mathematical representation ability in the first cycle was 68.75% was classified into the minimally good category, while in the second cycle, the students' mathematical representation ability had increased up to 93.75% and was classified into the minimally good category. based on the research results above, it can be concluded that the core (connecting, organizing. reflecting. and extending) learning model can improve the students' mathematical representation ability related to two-variable linear equation materials at the grade viii-s of smp negeri 5 tarakan. keywords: mathematical representation ability, core (connecting, organizing, reflecting, and extending) learning model