This study focused on developing Competency-based Learning Material in Performing Mensuration and Calculation and Evaluating the Effectiveness through the Performance Rate of Respondents. Specifically, the researcher aimed to determine the level of components and characteristics of the developed worktext; assess the students? performance through pretest and post-test, and identify the significant effect of the developed worktext on the student?s post-test. The researcher used a descriptive research method in the gathering of the data. The respondents are a total of fifty (50) Grade 8 Students enrolled for the School Year 2021-2022 with a grade in TLE lower than 80. The research instrument of this study utilized the pre-test and post-test. Moreover, the researcher also developed questionnaires assessing the level of components and characteristics of the worktext. The statistical treatment of mean difference, weighted mean, standard deviation, and t-test were used by the researcher