Abstract – This study focuses on the least mastered Most Essential Learning Competencies in mathematics 9. It was observed that having not mastered the learning competencies affects the academic performance of the learners so this study was conducted. In answer to the new normal education the researcher implemented an intervention called Project RLM (Rationalizing Localized Materials) the project focuses on how to deliver the lesson to the learners despite of all the challenges that are encountered cause by COVID – 19 pandemic. The researcher uses quasi – experimental design to measure the effectiveness of the usage of the intervention project RLM in enhancing the academic performance of grade 9 learners in Mathematics. The respondents of this study are the grade 9 learners of Batangan National High School, where in the researcher uses a total population sampling. The researcher utilizes a paired t – test to compare and see if there is a significant difference between the academic performance of grade 9 learners before and after the implementation of project RLM. The results shows that the null hypothesis was rejected where in there is a significant difference in academic performance of grade 9 learners before and after the implementation of project RLM. It was also concluded that the use of project RLM as an intervention provides a positive improvement in the academic performance in Mathematics of grade 9 learners of Batangan National High School. Hence, it was recommended that (a) continuous innovations of localized learning materials should be imposed. (b) Enhancing computer literacy skills by providing a correct trainings in innovating instructional materials. And (c) Constant assessment and evaluation of learners academic performance may be conducted.