THE STUDY OF MATHAYOMSUKSA 2 STUDENT' APTITUDE FOR MATHEMATICAL PROBLEM-SOLVING WHEN IT COMES TO APPLYING RATIOS AND PERCENTAGES USING TEAM-GAMES-TOURNAMENT TECHNIQUES COMBINED WITH THE BAR MODEL

In this research, the study focused on the use of collaborative learning with TGT technique combined with the Bar model to enhance the mathematical problem-solving. The collaborative learning with TGT technique combined with the Bar model approach stimulates students to interest in learning, find it enjoyable in learning, and an enthusiastic about studying. The research sample consists of 25 Mathayomsuksa 2 students at Khambokwittayakan School, Khamcha-e District, Mukdahan Province. Participants were randomly selected through Cluster random sampling method. The data were analyzed using the mean, percentage, standard deviation, and t-test. The research tools include lesson plan and mathematical problem-solving ability test. The research findings indicated that: 1) The mathematical problem-solving abilities of Mathayomsuksa 2 students after participating in collaborative learning with TGT technique combined with the Bar model have average score at 16.08 points and surpassed the 75 percentiles with statistical significance at the .05 level. 2) The mathematical problem-solving abilities of Mathayomsuksa 2 students after using collaborative learning with TGT technique combined with the Bar model were higher than those before using collaborative learning with TGT technique combined with the Bar model. The learning difference was statistically significant at the .05 level.