<![CDATA[ The aim of this research is to develop and produce Android application-based learning media on statistics material and improve the ability to understand mathematical concepts at Xth Class students. The population in this research is at Xth Class students of SMA Negeri 6 Tanjungbalai. The type of research used is R&D development research (research & development) using the 4D model (define, design, development, disseminate). The results of this research are Android application-based learning media on statistics material. Based on validity tests assessed by 2 material experts, 2 media experts and 1 mathematics subject teacher with an average assessment percentage of 96% in the very valid category. Meanwhile, practicality testing was carried out by the teacher response questionnaires and student response questionnaires with an average assessment percentage of 97% in the very practical category, and to test effectiveness through tests of students' ability to understand mathematical concepts with average student learning outcomes. of 95% in the complete category. classically, and the observation results have an average assessment percentage of 96% in the very effective category. It can be concluded that the Android application-based statistical material learning media using the REACT model to improve the ability to understand mathematical concepts at Xth Class students of SMA Negeri 6 Tanjung Balai is valid, practical and effective.Keywords : Learning media, Android applications, REACT model, ability to understand mathematical concepts]]>
