This study was conducted to determine the influence of an integrated approach combining TPACK (Technological Pedagogical Content Knowledge), ICT (Information and Communication Technology), HOTS (Higher Order Thinking Skills), and the 4C skills (Critical Thinking, Creativity, Collaboration, Communication) on students' understanding of mathematical concepts. The population comprised all eighth-grade students at SMP Negeri 1 Padangsidimpuan, North Sumatra, Indonesia. Through random class sampling, two classes were selected: Class VIII-1 was assigned as the experimental group, and Class VIII-2 as the control group. This design was chosen to examine the causal influence of the independent variables on the outcome while maintaining the practical constraints of the school setting. Utilizing a quasi-experimental design, the study involved two sample classes: an experimental class, where the integrated approach was implemented, and a control class, which followed conventional teaching methods. The primary research instruments comprised observation sheets to assess both teacher implementation fidelity and student engagement during the learning process, alongside a test sheet specifically designed to measure students' mathematical concept understanding. Data analysis employed both descriptive techniques, to detail teaching and learning activities and categorize levels of conceptual understanding, and inferential statistics, to rigorously test the study's hypothesis. The quantitative findings from the observation data revealed a distinct difference in implementation between the classes. In the experimental class, teacher activity in applying the TPACK, ICT, HOTS, and 4C framework showed consistent improvement, with an average implementation rate of 87.5% across four meetings. Correspondingly, student activity aimed at enhancing concept understanding averaged 82%. While there were minor shortcomings, such as initial adjustments to the new method and occasional lapses in pre-lesson guidance or summarizing activities (accounting for a 12.5% non-implementation rate), these had a minimal impact (only 2.5%) on the overall learning outcomes. In contrast, the control class, which used a more conventional innovative method, achieved a lower average teacher implementation rate of 84.72%, with persistent issues like insufficient guidance in drawing conclusions. The core outcome of the study is derived from the inferential analysis. The hypothesis test indicated a statistically significant difference in the average scores of mathematical concept understanding between the experimental and control groups. This empirical evidence leads to the conclusive finding that the synergistic application of TPACK, ICT, HOTS, and 4C exerts a significant and positive influence on enhancing students' comprehension of mathematical concepts. The research underscores the effectiveness of this integrated modern pedagogical framework in creating a more engaging and cognitively demanding learning environment that fosters deeper conceptual mastery in mathematics.