The research entitled The Development of Learning Activity through KWDL Technique Combined with BAR Model to improve problem-solving Ability in Math for Secondary 1 (Grade 7) Students made use of a quasi-experimental design wherein the experimental group was exposed to learning activities through the KWDL technique combined with BAR model while the control group learned through traditional. The sample used in this research was 38 Secondary 1 (Grade 7) students from Rizal National Science High School, Rizal Province, Philippines who studied in the second semester of the academic year 2022 by cluster sampling. The research instruments consisted of 1) learning management plans with learning activities through traditional; 2) learning management plans with learning activities through the KWDL technique combined with the BAR model; 3) problem-solving ability in a Math test. Data analysis included mean, standard deviation, and t-test. The results showed that: 1) the problem-solving ability in Math of Secondary 1 (Grade 7) students after studying learning activities through the KWDL technique combined with the BAR model was higher than before learning at a statistical significance level of 0.05 level; 2) the problem-solving ability in Math of Secondary 1 (Grade 7) students after studying learning activities through traditional was higher than before learning at a statistical significance level of 0.05; 3) the problem-solving ability in Math of Secondary 1 (Grade 7) students studying learning activities through KWDL technique combined with BAR model was higher than the learning activities through traditional at statistical significance level of 0.05.