This quantitative study aimed to determine the level of acceptability of the developed and validated instructional material in teaching fraction among the grade 5 pupils, who are officially enrolled in Pis-anan Central School, District of Sibalom South during the School Year 2023-2024. This study used the design-based research using the analysis, design, development, implementation, and evaluation (ADDIE) model. The respondents of the study were all the 47 Grade 5 pupils officially enrolled in Pis-anan Central School. Data were gathered using the researcher-made instrument duly validated by the experts. Data were analyzed using the Statistical Packages for Social Sciences (SPSS) version 22. The findings of the study revealed that while grade 5 pupils performed well in solving addition and subtraction fraction problems, they struggled with creating problems, particularly those involving division and multiple operations. The implementation of specially designed instructional material addressing these least mastered competencies led to significant improvements in pupils’ mastery levels of fraction operations, as evidenced by pre and posttest comparisons. Moreover, the instructional material was highly accepted for their content quality and effectiveness in enhancing understanding and problem-solving abilities in fractions.