Abstract
This study aimed to develop and evaluate the supplementary learning materials for the least mastered competencies of senior high school students in Earth and Life Science in San Roque National High School in Marikina City during the school year 2021 – 2022. The method of research used in the study was the descriptive type with the survey questionnaire as the data gathering instrument. The gathered data were treated statistically using ranking, weighted mean, independent-sample t test, and paired-sample t test. The findings showed that the least mastered topics based on the summative test results for the last two years were used in the developed supplementary learning materials. The Science teacher respondents obtained the overall weighted mean of 3.56 with verbal interpretation of Very Satisfactory, while the Science expert respondents got an overall weighted mean of 3.40 which is verbally interpreted as Satisfactory. Regarding accuracy and up-to-datedness of information, the Science teachers and Science experts’ respondents got the overall weighted means of 3.71 and 3.77 which were both verbally interpreted as Not Present. In addition, there was a significant difference between the pretest and posttest mean scores of the respondents. Comments and suggestions were given by the respondents to further enhance the developed material.
