Recardo O. Sanditan Jr.^1,, Dennis B. Roble¹

The effectiveness of instructional approaches in developing students' mathematical problem-solving skills remains a critical concern in Philippine senior high schools. This study examined the effect of the Math Workshop Model (MWM) on Grade 11 students' problem-solving abilities. Using a quasi-experimental pretest-posttest control group design, the research involved 66 Grade 11 HUMSS students from Pedro "Oloy" N. Roa Sr. High School, Cagayan de Oro City, during the 2025-2026 academic year. The experimental group received instruction through the Math Workshop Model, featuring mini-lessons, differentiated work time, sharing sessions, and reflection activities, while the control group was taught using traditional lecture-based instruction. Before analysis, ANCOVA assumptions, including homogeneity of regression slopes, normality of residuals, and homogeneity of variance, were tested and confirmed. Results revealed that both groups improved from pretest to posttest; however, the experimental group demonstrated substantially greater gains. ANCOVA confirmed a statistically significant difference between groups (F (1, 60) = 13.93, p < .001, η² = 0.182), with a large effect size indicating that the MWM was significantly more effective in enhancing students' problem-solving skills. These findings suggest that the structured, student-centered approach of MWM provides a promising framework for improving mathematical problem-solving in senior high school contexts.

Math Workshop Model, problem-solving skills, ANCOVA, quasi-experimental, senior high school mathematics