Abstract
Mathematics learning outcomes among elementary school students on data topics remain low due to teacher-centered instruction and limited use of concrete learning media. This study aims to improve mathematics learning outcomes through the implementation of the Problem Based Learning (PBL) model supported by “Zone Diagrams”. This Classroom Action Research (CAR) employed the Kemmis and McTaggart model and was conducted in two cycles, each consisting of planning, action, observation, and reflection. The subjects were 30 Grade V-B students at SDN 02 Mojorejo. Data were collected through learning achievement tests and analyzed using quantitative descriptive methods by calculating mean scores and learning mastery percentages. The results showed that the implementation of PBL supported by Zone Diagrams improved student learning outcomes. The class average increased from 54 in the pre-cycle to 69 in Cycle I and 83 in Cycle II. Learning mastery also increased from 20% in the pre-cycle to 53% in Cycle I and 90% in Cycle II, exceeding the predetermined success indicator. These findings indicate that integrating PBL with Zone Diagram media can create a more active, contextual, and meaningful learning experience, thereby improving students’ understanding and learning outcomes in the data topic