ANALYSIS OF THE STUDENTS’ MATHEMATICAL CONCEPTUAL UNDERSTANDING ABILITY ON SEQUENCES AND SERIES MATERIAL IN SENIOR HIGH SCHOOL

Mathematical concept understanding is one of the important competencies in learning mathematics, especially in the material of sequences and series. Based on observations, grade X high school students have difficulty in distinguishing arithmetic and geometric sequences and applying formulas correctly. This study aims to evaluate the ability of grade X students in understanding mathematical concepts of sequences and series material. This study uses a descriptive qualitative research type. Data were collected through a test instrument consisting of 5 essay questions and a non-test instrument consisting of interviews. Students of X.11 SMAN 1 Telagasari consisting of 34 students were selected for the study. Then, reducing the students to 3 people, each representing a category of conceptual understanding ability: 1 student with high ability, 1 student with moderate ability, and 1 student with low ability. Data analysis involves three steps: reducing data, displaying data, and drawing conclusions. The results of the study showed that students with high understanding were able to meet all indicators of conceptual understanding, while students with moderate understanding only mastered several indicators, and students with low understanding had difficulty in understanding the concept almost completely. These findings indicate the need to implement more interactive and exploration-based learning strategies to help students understand concepts in depth so that students' conceptual understanding can improve.