Abstrak
This research aims to investigate the effect of self-concept, study habits, and both self-concept and study habit on students’ mathematics achievement at SMP Muhammadiyah 2 Tarakan. This research was conducted in the even semester 2021/2022. The type of research was quantitative research with survey methods. The sample was 63 students of IX class of SMP Muhammadiyah 2 Tarakan. Data collection techniques used by distributing self-concept questionnaires and study habits and mathematics learning outcomes documents. The data obtained through statistical data processing program, namely 25.0. The results can be revealed that there was a partially significant effect between self-concept on mathematics learning achievement of class IX wits the regression equation 1 = 32,703 + 0,383 X, and there was a partially significant effect between study habits on students’ mathematics achievement with the regression equation 2 = 39,344 + 0,291 X. In addition, the results of the research also showed that there was a simultaneous significant effect between self-concept and study habits on the mathematics learning outcomes of class IX students with the regression equation = 27,208 + 0,329 X1 + 0,129 X2. Based on the calculation of coefficient of determination, it was revealed that self-concept and study habits simultaneously had an effect of 10.9% on the mathematics learning outcomes of class IX students of SMP Muhammadiyah 2 Tarakan.