<![CDATA[This study was motivated by the low understanding of integer concepts among fifth-grade students at SD Inpres Perumnas Antang I. In addition, the learning process had not fully encouraged active student engagement in mathematics lessons. This study aimed to: (1) describe the implementation of the Game-Based Learning model assisted by Chain Octopus media on integer learning; (2) describe students' understanding of integer concepts; and (3) analyze the effect of the model implementation on students' understanding of integer concepts. This study employed a quantitative approach with a quasi-experimental method using a pretest-posttest non-equivalent control group design. The sample consisted of 53 fifth-grade students selected through purposive sampling, divided into an experimental class (VA, n=26) and a control class (VB, n=27). The experimental class was treated using Game-Based Learning assisted by Chain Octopus media, while the control class used Direct Instruction. Data were collected through tests (pretest and posttest) and observation sheets, then analyzed using descriptive and inferential statistics (Mann-Whitney test). The results showed that the implementation of the Game-Based Learning model assisted by Chain Octopus media was categorized as very good (86.11% in the first meeting and 97.22% in the second meeting). Students' understanding of integer concepts in the experimental class improved from a pretest mean of 40.27 to 71.62 (N-Gain 0.5420 medium category), while the control class increased from 36.41 to 57.48 (N-Gain 0.3278 medium category). Hypothesis testing using the Mann-Whitney test showed a significance value of 0.011 (<0.05), indicating a significant difference after the treatment. Therefore, the Game-Based Learning model assisted by Chain Octopus media is effective in improving fifth-grade students' understanding of integer concepts.]]>
