This study presents the application of the project based learning model on the sum of integers. this research uses the lesson study for learning community (LSLC) system. The sample of this study was 22 seventh grade students of Srijaya State Junior High School Palembang. The research method used is design research (design research). This study designs project based learning based on account calculations. The stages of this study consisted of experimental preparation, design experiments and retrospective analysis. Based on the results of retrospective analysis, it is shown that by using electricity account calculations as a context in learning students can understand integers and sets.

No abstract