Memahami suatu konsep merupakan hal mendasar dalam proses pembelajaran. Melalui hasil pengamatan pada siswa kelas II SD ABC Sentani, Papua, terlihat adanya kesulitan dalam memahami konsep pada pelajaran matematika. Hal ini dikarenakan kurangnya sumber belajar di sekolah. Selain itu, faktor dari masing-masing siswa seperti siswa yang tidak naik kelas dan butuhnya perlakuan khusus. Oleh karena itu, peneliti menerapkan metode drill untuk meningkatkan pemahaman konsep siswa pada topik penjumlahan susun pendek. Metode drill diterapkan dengan cara melatih siswa secara terus menerus sehingga siswa mampu memahami konsep penjumlahan susun pendek. Dalam penelitian ini, peneliti menggunakan metode Penelitian Tindakan Kelas (PTK). Penelitian dilakukan pada tanggal 3 Agustus 2015 hingga 13 November 2015 dengan melibatkan 18 siswa. Adapun instrumen yang digunakan yakni lembar tes, lembar observasi mentor, lembar check list mentor, lembar wawancara mentor dan lembar angket siswa. Dalam menganalisis instrumen tersebut, peneliti menggunakan teknik analisis secara deskriptif kualitatif. Penerapan metode drill mampu meningkatkan pemahaman konsep siswa hingga 100% pada siklus kedua. Metode drill diterapkan sesuai dengan langkah�langkahnya yaitu persiapan metode, cek pemahaman siswa, penekanan poin pelajaran, latihan, dan tes tertulis, serta merubah posisi duduk siswa dan penggunaan warna spidol yang berbeda. Berdasarkan hasil tersebut,penelitian ini dapat dikatakan berhasil karena dapat mencapai kriteria keberhasilan yaitu ≥76% dari jumlah siswa/ Understanding a concept is a basic in the learning process. Through observations in grade II students at ABC Sentani primary school, Papua, there were difficulties in understanding the concept in mathematics. This was due to the lack of learning resources at the school. Besides that, the factors of each student, like the student who failed a grade and needed a special treatment. Therefore, the researcher applied drilling method to improve the students’ conceptual understanding in columnar addition topic. Drilling method was applied to the students by continuous drilling so that the students would be able to understand the concept of columnar addition. In this research, the researcher used the method of Classroom Action Research (CAR). The research was conducted on August 3rd, 2015 until November 13th, 2015, involving 18 students. The instruments used were test sheet, mentor observation sheet, mentor checklist sheet, mentor and student questionnaire sheet. In analyzing the instruments, the researcher used qualitative descriptive analysis technique. The implementation of drilling method could improve the students’ conceptual understanding up to 100% in the second cycle. Drilling method was applied in accordance with the steps which were the procedure setting the scene, checking meaning and understanding, emphassing key learning point, drilling, and giving written test also changed students’ posisition and use many colour when descript the material. The research was successful according to the result, because it could achieve the success criterion which was ≥76% of the total number of students.