The purpose of this classroom action research is to improve student learning outcomes on the flat shape material for fifth graders at SD Negeri Banyuurip. The research was carried out in 2 cycles. Cycle I was held on 13 and 16 April 2022 and Cycle II was held on 20 and 23 April 2022. The research model used in this classroom action research consisted of 4 stages, namely planning, implementation, observation and reflection. Data collection techniques through observation and formative tests. The data analysis technique used a comparative description, namely by comparing scores of pre-cycle, cycle I and cycle II. The results showed that by applying the discovery learning model, student activity increased so that student learning achievement also increased. This can be seen from the data from the observation of student learning activity obtained by 25% in the pre-cycle, increasing to 35.14% in the first cycle and 81.24% in the second cycle. The results of the concept understanding test also increased, students who finished learning and 16.67% before the improvement became 41.66% in the first cycle and 83.33% in the second cycle with an average value in the initial learning of 54.17 to 66.67 in the first cycle. the first cycle then in the second cycle to 84.17.