<![CDATA[This research was motivated by the low level of mathematical concept understanding among third-grade elementary school students. This issue stemmed from a teaching process that remained teacher-centered. Instruction tended to be one-way, with students merely receiving information from the teacher rather than engaging in a meaningful learning process. Consequently, students relied more on rote memorization than on understanding the fundamental concepts of the material. Furthermore, observations revealed that the teacher did not utilize instructional media during lessons, causing students to become easily bored and struggle to grasp the material. The objective of this study was to enhance students' understanding of mathematical concepts and the teacher's instructional skills through the implementation of the TGT model supported by GANTA. The study employed the Classroom Action Research (CAR) method based on the Kemmis and McTaggart model, which requires multiple cycles to achieve success. Conducted at SD Muhammadiyah 1 Kudus, the study involved 29 third-grade students. The data indicated that students' understanding of mathematical concepts improved from a range of 53.79%–59.14% (with a 31% mastery rate) to 75.17%–87.41% (with an 82.76% mastery rate), while the teacher's instructional skills improved from 68,45% to 94.64%. These results demonstrate that implementing the TGT model supported by GANTA effectively enhances both students' understanding of mathematical concepts and the teacher's instructional skills.]]>
