Penerapan discovery learning dalam meningkatkan kemampuan berpikir kritis dan ketuntasan belajar matematika

The purpose of this study is to explain and observe the improvement of critical thinking skills and students' mathematics learning completeness in mathematics lessons through discovery learning-based learning. This study is included in Classroom Action Research or PTK, with the research subjects being 33 students of class IX D of SMP Negeri 6 Surabaya. The research techniques and instruments used are test techniques and written test sheets. Then, the data obtained are processed and presented as a percentage. The results of this study show that (1) there is an increase in students' critical thinking skills by 91.60% in the indicator of analyzing learning in 2 cycles that have been implemented using the discovery learning model (2) students' learning completeness in mathematics learning also shows an increase at the end of the cycle, namely the number of students who have completed as many as 27 students with an average score of 91.60. So, it can be concluded that the application of discovery learning in mathematics learning can improve students' critical thinking skills and learning completeness in the material of curved side space shapes.