Abstrak—Penelitian ini bertujuan untuk mengkaji penerapan strategi pembelajaran Active Learning tipe Index Card Match dalam meningkatkan pemahaman konsep matematika siswa sekolah dasar. Latar belakang penelitian ini adalah rendahnya pemahaman siswa akibat dominasi metode ceramah yang membuat siswa pasif, kurang termotivasi, dan mengalami kesulitan dalam memahami konsep matematika. Penelitian menggunakan pendekatan kualitatif dengan jenis studi kasus, melibatkan guru, siswa, dan kepala sekolah di SD Islam Al-Huda 2 Kota Kediri. Data dikumpulkan melalui observasi, wawancara, dan dokumentasi. Analisis data dilakukan dengan reduksi data, penyajian data, dan penarikan kesimpulan. Hasil penelitian menunjukkan bahwa strategi Index Card Match menciptakan suasana belajar yang aktif, menyenangkan, dan kolaboratif, sehingga siswa lebih bersemangat, berani berinteraksi, dan menunjukkan peningkatan pemahaman konsep matematika. Kendala yang muncul antara lain suasana kelas yang ramai dan kesulitan memahami isi kartu. Guru perlu merancang materi, instruksi, dan pengelolaan kelas yang baik agar strategi ini berjalan optimal. Temuan ini mendukung pentingnya penerapan metode aktif dalam pembelajaran matematika sebagai upaya meningkatkan pemahaman konsep siswa Kata Kunci : Active Learning, Index Card Match, Pembelajaran Matematika, Pemahaman Konsep Abstract— This study aims to examine the application of the Active Learning strategy, specifically the Index Card Match type, in improving elementary school students’ understanding of mathematical concepts. The background of this research lies in the low level of students’ comprehension caused by the dominance of lecture methods that make students passive, less motivated, and struggling to grasp mathematical concepts. The study employed a qualitative approach with a case study design, involving teachers, students, and the principal at SD Islam Al-Huda 2 Kediri. Data were collected through observation, interviews, and documentation. The data were analyzed using the stages of data reduction, data display, and conclusion drawing. The findings revealed that the Index Card Match strategy created an active, enjoyable, and collaborative learning atmosphere, making students more enthusiastic, willing to interact, and demonstrating improved understanding of mathematical concepts. However, challenges emerged, such as noisy classroom conditions and difficulties in comprehending the content of the cards. Teachers are therefore required to design appropriate materials, provide clear instructions, and manage the classroom effectively to optimize the implementation of this strategy. These findings highlight the importance of applying active learning methods in mathematics instruction as an effort to enhance students’ conceptual understanding. Keywords : Active Learning, Index Card Match, Mathematics Learning, Conceptual Understanding