The background of this research is students' low learning outcomes on mathematics. This study aimed to improve students' mathematics learning outcomes through the Discovery Learning model. This classroom action research was carried out in two cycles, each cycle consisting of two meetings, each meeting held 3x35 minutes. This research consisted of four stages in the form of planning, action, observation, and reflection. The subjects of this study were 39 fifth graders of SD Negeri 1 Pliken consisting of 19 male students and 20 female students. The data collecting techniques of this study were test and non-test techniques. Data collecting used in this study were written test questions, teacher and students activities observation sheets, psychomotor affective observation sheets. Improved learning outcomes occurred in the first cycle to cycle II. The average cognitive learning outcome of students in the first cycle was 68.98 with the learning mastery percentage of 69.24%. The average cognitive learning outcome of students in the second cycle was 83.85 with 84.62% learning mastery. In the first cycle, the results of affective learning obtained an average score of 2.17 with sufficient criteria. In the second cycle, the results of affective learning obtained an average score of 3.18 with good criteria. In the first cycle, psychomotor learning outcomes gained an average score of 1.99 with sufficient criteria. In the second cycle psychomotor learning outcomes gained an average score of 3.16 with good criteria. The results of this study indicated that the use of the Discovery Learning model was able to improve students' mathematics learning outcomes of on data presentation material in the fifth grade of SD Negeri 1 Pliken, Kembaran District, Banyumas Regency