<![CDATA[The purpose of this study was to measure the effectiveness of the open-ended approach assisted by the Genially platform on students' mathematical problem-solving abilities. The research method used was quantitative with an experimental method. The design used was Quasi Experimental with a Non-equivalent Pretest-Posttest Control Group Design. The sampling technique used was purposive sampling, with two classes divided into one experimental class of 36 students who received the treatment and one control class of 36 students who did not receive the treatment. The total sample in this study was 72 students. The instruments used in the study were test questions (pretest & posttest) on mathematical problem-solving skills and a questionnaire. The data analysis techniques used were the independent sample t-test, the Mann-Whitney U test, N-Gain analysis, and questionnaire processing. The analysis of initial ability showed a Sig. (2-tailed) value of 0.482 ≥ 0.05. Therefore, there was no significant difference in the initial mathematical problem-solving ability of the students. After both classes were given different treatments, the results showed Sig. (2-tailed) 0.000 ≤ 0.05, indicating a significant difference in problem-solving ability between the control class and the experimental class. The questionnaire results showed that the students gave positive responses and demonstrated high interest. The open-ended approach and the Genially platform are effectively used in mathematics learning to enhance students' mathematical problem-solving skills.]]>
