This research aims to develop online mathematics learning tools based on the local wisdom of Papua in the form of Lesson Plan and E-Worksheet products that are oriented to students' critical thinking skills and mathematical problem-solving in materials of polyhedra which (1) validity aspects, (2) practicality aspects, (3) effectiveness aspects. The cultures used in this research are the kariwari traditional house and the kaki seribu traditional house as illustrations to explain the concept of polyhedra. The research method is research and development (R&D) using the ADDIE (Analysis, Design, Development, Implementation, and Evaluation) development design model. The subjects in this study are 8 students who are in grade VIII at Golden Gate Junior High School, Sorong City. The instruments used in this study are validation sheets, learning implementation observation sheets, teacher response questionnaires, student response questionnaires, and tests. The learning tool is valid if the results of the experts' assessment are at least in the "good" category. Learning tools are said to be practical if the results of teacher’s responses, student responses, and observations of learning implementation are at least in the "good" category. The learning tool is effective if the percentage of students who complete the critical thinking skills test and the math problem-solving ability test is at least 60%. This research produced online learning tools in Lesson Plan and E-Worksheet mathematics form based on local Papuan wisdom oriented to critical thinking skills and problem-solving skills of grade VIII junior high school students on flat-side space building materials. The validation results show that the product developed meets the valid criteria with a good category. The results of the test show that the product developed meets the practicality and effectiveness criteria. Practicality achieved the category “very good” based on teacher assessment, student responses, and the observation of learning implementation. Effectiveness achieves the effective category based on the test of critical thinking skills and mathematical problem-solving. The percentage of students who completed the critical-thinking skills test reached 87.50%, and the mathematical problem-solving ability test reached 75.00%.
