<![CDATA[Indonesia’s ongoing education policy keeps pushing for better learning quality, with particular attention to 21st-century competencies such as higher-order thinking. A module built around self-regulated learning and probing prompting offers one such tool, since it targets a specific higher-order skill: mathematical reasoning. This study set out to build a mathematics learning module that meets the standards of validity, practicality, and effectiveness for strengthening students’ mathematical reasoning. It followed a Research and Development (R&D) design based on the five ADDIE stages—Analyze, Design, Develop, Implement, and Evaluate—with class X E-9 students at SMA Negeri 3 Purwokerto as the research subjects. Expert validation produced an average score of 3.76 for the media component and 3.80 for the material component, giving an overall score of 3.81 in the very valid category. Practicality testing likewise returned an average of 3.31 from student responses and 3.91 from teacher responses, both rated very practical. For effectiveness, an N-Gain analysis produced a mean gain of 0.591, placing it in the medium category and confirming the module’s effectiveness in improving students’ mathematical reasoning. Taken together, these findings show that the module satisfies the validity, practicality, and effectiveness criteria and is therefore fit for use as teaching material to strengthen students’ mathematical reasoning in mathematics instruction.]]>
