Learning Trajectory in Problem-Based Mathematics Learning with Literacy and Numeracy Reinforcement: An Implementation of Lesson Study at Junior High School

This study aims to explore the learning trajectory of problem-based with literacy and numeracy reinforcement. was conducted at Junior High School involved 32 subjects from class VIII. employed Gravemeijer Cobb's design research comprising three stages: preparing experiment hypothetical (HLT), designing by implementing designed HLT-based learning, conducting retrospective analysis comparing HLT implemented learning. The in this consisted components: objectives, a series tasks activities, students' techniques think learn. based on lesson activities create for community. Design stages corresponded included studying curriculum, formulating goals plans, lessons, reflecting lesson. has revealed that actual four levels modeling: situational, referential, general, formal levels. At situational level, non-mathematical becomes initial reference students collaborate communicate others; thus, mathematical concepts are created. referential level leads represent real problems concepts. representation process understand concept different situations. Finally, analogize acquired understanding bring it get full one point position another Cartesian coordinates.