This study aimed to determine the effectiveness of the KLR Model as an intervention in mastering integer addition and subtraction among Grade 7 students. The purpose of this experimental-qualitative study was to address difficulties in mastering these operations. The participants were 15 Grade 7 students from Asuncion National High School. The study introduced an intervention called the KLR Model (Keep it Simple, Learn the Rules, Reach Mastery), a tutorial approach aimed at enhancing students' arithmetic skills through engaging learning strategies. The pre-test and post-test results showed a significant improvement: the pre-test had a mean score of 7.39, while the post-test showed a mean score of 12.61. A paired-samples t-test revealed a statistically significant difference between the two scores, t(14) = 9.35, p < .001, indicating a highly significant improvement in integer mastery following the intervention. These findings suggest that the KLR Model effectively improved students’ performance in integer operations. To provide a comprehensive understanding of the students' experiences, the researchers conducted in-depth interviews with selected participants. From their responses, nine themes emerged: Active Participation Enhances Understanding, Visual Tools Support Concept Formation, Student-Constructed Rules Deepen Understanding, Solving Independently Builds Confidence, Peer Interaction Encourages Collaboration, Conflicting Ideas Within Groups Pose a Challenge, Need for Immediate Feedback, Learning Process Improves Self-Esteem, and Self-Discovery Boosts Interest.