<![CDATA[This study aimed to develop Kidz Land, a game-based mathematics learning media for second-grade elementary school students, and to examine its validity, effectiveness, and practicality in supporting mathematical problem-solving skills. This research employed a Research and Development (R&D) design using the ADDIE model, consisting of five stages: analysis, design, development, implementation, and evaluation. The participants were 20 second-grade elementary school students. Data were collected through material and media expert validation sheets, pretest and posttest instruments, observation sheets, and teacher and student response questionnaires. The results showed that Kidz Land achieved validity scores of 75% from the material expert and 77.5% from the media expert, indicating that the developed media was suitable for use with minor revisions. The effectiveness analysis revealed a significant improvement in students’ mathematical problem-solving scores, with the mean score increasing from 49.65 on the pretest to 86.60 on the posttest (t(19) = −16.316, p < .001). The normalized gain was 0.73, categorized as high. Practicality results indicated that students could operate the game easily and demonstrated high engagement during learning activities, while teachers reported that the media facilitated instruction. Therefore, Kidz Land is a valid, effective, and practical game-based learning medium for supporting elementary students’ mathematical problem-solving skills. Further research should involve larger samples and comparison groups.]]>
