Abstract
This study aimed to know the effectiveness of learning devices to improve students’ mathematical reasoning ability. Teachers should be able to design learning processes that are interactive, inspiring, fun, challenging and motivate students to participate actively in the learning process. The learning planning designed was Syllabus, RPP, and LKPD. Reasoning ability should be possessed by students, however in reality students’ reasoning ability is still low. There are still shortcomings in teaching materials are also the background of the author developing LKPD. The solution of improving the learning process and reasoning of students is to see the effectiveness of learning devices based on the discovery learning model. The developmental model used was a 4-D model. The data collection instruments of this study were in the form of validation sheets, learner response questionnaire sheets, teacher response questionnaire sheets, and students’ mathematical reasoning ability tests. The results of the analysis of practicability data on the small group trial of the learners’ response questionnaire showed the very practical category and the efficacy of the reasoning ability test results of the learners showed the category as very practical and more effective meaning that the applied learning device was more effective on students’ reasoning ability.mathematics. The revised learning device is then made a product of the research findings. The results of the study analyzing the effectiveness of learning devices to improve the reasoning ability of VIII grade learners SMPN 25 Pekanbaru has been very effective.