This study determined the learning gains of Grade 6 learners in Mathematics lessons using Concrete-Representational-Abstract (CRA) approach. It was conducted in Matangpatang Elementary School, Schools Division of Malaybalay City, Philippines during the school year 2018-2019, that was participated by twenty learners. One group pretest-posttest quasiexperimental research design was used in the study. Lessons incorporating the CRA approach and researcher-made performance test were validated by a panel of experts in terms of content and content accuracy, clarity, and appropriateness. The results of their evaluation were taken into consideration in the revision of the developed lessons and test. Further, the revised performance test was tested for reliability and the result was 0.863, which means that the instrument is consistent to assess the performance of learners. The data gathered were analyzed and interpreted using appropriate statistical techniques. Mean, standard deviation, frequency, percentage, and paired t-test were used. Results revealed that before Grade 6 learners were taught using CRA Approach, their academic performance was at Did Not Meet Expectations level. However, after they were taught using Concrete Representational Abstract Approach, they reached Fairly Satisfactory level. In addition, there is a significant difference in the learning gains of Grade 6 learners before and after they were taught using the said approach.