Use of valid and appropriate instructional material contributes in the attainment of quality learning. Facilitators in the teaching-learning process must consider variety of teaching tools to cater the different needs of the students. Nowadays, this could be easily done through the integration of modern technology. This study aimed to develop and validate off-line Web Quest to determine the effects on the cognitive and affective skills of Grade 7 students in Gatbo National High School, Division of Sorsogon City for the SY 2022-2023. This study utilized the descriptive –developmental research method as the general research design. The observational and survey research and mixed method approach (sequential explanatory design) were also employed. The data collected were analyzed and treated using statistical tools such as weighted mean, t-test and Cohen’s d. Findings revealed that the 7 Mathematics education experts have agreed that the developed off-line web quest is a valid instructional tool for teaching the fundamental operations on integers. It was also revealed that the use of the developed off-line web quest is effective on both cognitive skill and intrinsic motivation of the students.