The design research method was used in this study with the aim to determine the role of treasure finding a context in supporting the learning process using the PMRI approach that could help the students understanding mean concepts in the seventh graders. The implementation of this study consisted of three stages: preparing for the experiment, the experiment design, and retrospective analysis. This study was conducted in State Junior High School 1 North Indralaya, with the samples were 35 students of seventh graders. The data collection techniques used in this study were observation, interview, field notes, and written tests. The results of this study were in the form of a learning trajectory that included two learning activities starting from the use context of the treasure finding and by splitting the treasure evenly, then solved the problem in daily life. These activities could help students understand mean concepts.