Penelitian ini dilatarbelakangi oleh rendahnya kemampuan berpikir  kritis matematis dan kepercayaan diri siswa SMP. Untuk mengatasi permasalahan tersebut diperlukan salah  satu  pendekatan  pembelajaran  yang  diharapkan  mampu  mengembangkan kemampuan berpikir kritis matematis dan kepercayaan diri siswa  adalah pendekatan open ended. Melalui pembelajaran ini, siswa terlibat langsung dan belajar mengeluarkan ide-ide dalam menyelesaikan soal-soal bersifat open ended, sehingga membangkitkan minat siswa untuk aktif selama proses pembelajaran. Diharapkan melalui pembelajaran ini, siswa menjadi termotivasi, ulet dan bersungguh-sungguh dalam memahami matematika sehingga dapat meningkatkan kepercayaan diri siswa. Bentuk luaran dari penelitian ini berupa produk bahan ajar bersifat open ended yang dapat dimanfaatkan oleh guru dalam pembelajaran. Metode penelitian yang digunakan adalah quasi experimental dengan bentuk desain Nonequivalent Control Group Design, dimana subyek penelitian tidak dikelompokkan secara acak. Populasi dalam penelitian ini adalah siswa SMP kota Cimahi, sedangkan sampelnya SMP Taruna Mandiri kemudian diambil dua kelas secara acak kelas, diperoleh kelas 7B sebagai kelas eksperimen dan kelas 7C sebagai kelas kontrol. Pengumpulan data dalam penelitian ini berupa tes sebanyak 5 soal uraian kemampuan berpikir Kritis dan 20 butir soal skala sikap kepercayaan diri dalam belajar matematika, kemudian data tersebut dianalisis dengan statistik deskriptif dan inferensial dengan menggunakan uji perbedaan dua rata-rata. Berdasarkan hasil penelitian, baik dari hasil analisis data maupun pengujian hipotesis, maka penulis menyimpulkan bahwa peningkatan kemampuan berpikir kritis dan pencapaian kepercayaan diri dalam belajar matematik siswa yang pembelajarannya menggunakan pendekatan open-ended lebih baik daripada pendekatan konvensional. Kata kunci:           Kemampuan  Berpikir Kritis matematis, Kepercayaan Diri, Pendekatan Open Ended

This research is motivated by the low ability of mathematical creative thinking of high school students of class X IPA. To overcome these problems required one of the learning models are expected to develop creative thinking skills and mathematical disposition of students is based on Alternative Solutions Worksheet. Through this learning, students are directly involved and learn to come up with ideas in solving open ended problems, so that the students interest to be active during the learning process. It is expected that through this learning, students become motivated, resilient. The output form of this research is an open ended alternative worksheet solution which can be utilized by teachers for teaching materials. The research method used is quasi experimental with design form of Nonequivalent Control Group Design, where the research subjects are not grouped randomly. The data in this study were collected through the pretest and posttest of mathematical ability as well as the scale of the students' mathematical disposition. The results of this study are classes that use learning alternative solution worksheet better than conventional class.

This research seeks to explore and reveal students' mathematical problem solving abilities by analyzing student answers. The research subjects were seventh grade students taken from a public junior high school in Purwakarta Regency. The results of the study show that students' mathematical problem solving ability is still very weak and far to be complete even though the level of difficulty of the instrument is in the medium category. In general, the ability of these study subjects in mathematical problem solving is still below 50%. It is time for teachers to apply problem-based learning, in addition to conventional learning models, to provide opportunities and experiences for students to see and experience mathematical problem solving in the classroom. This qualitative study exposes students' responses in dealing with story questions in a rectangular building material. In addition the students are given the questions shown to reveal whether the students are using a systematic solution or can answer directly without a sequence, judging by the ability to solve mathematical problems. There were 6 heterogeneous students who were the subjects in this study. Based on the analysis that has been done, the results obtained are (1) students answer the problem is not systematic, (2) lack of understanding of the sequence of problem solving, (3) students are too hasty in doing math problems.

This study aims to describe the thinking process of junior high school students in solving mathematical problems reviewed based on cognitive style field dependent and field independent. The method used in this research is descriptive qualitative research method, while the method of data retrieval is test and interview. The study conducted on the VII grade students of SMPN 2 Marga Asih.The subjects of the study were 2 students from junior high school consisting of 1 students with cognitive field dependent and 1 student style with an independent cognitive field. The results showed that there were significant differences between the two subjects in processing information, that was the subject of FI understand the problem better when compared with the subject of FD. Because if processing information was not stored properly, it will be very influential in the next step.

This study aims to analyze the creative thinking abilities of junior high school students in the Triangle and Quadrilateral material. The method used in the preliminary study is descriptive qualitative, which aims to analyze the ability of students to solve triangular and quadrilateral problems seen from the level of mathematical creative thinking ability of junior high school students. The population in this study were junior high school students in the city of Cimahi and the sample for this study were 36 eighth grade students in one of the junior high schools in the city of Cimahi. The instrument of creative thinking ability test is given as many as 5 questions with the type of description. Then the results obtained are the level of mathematical creative thinking ability of junior high school students in the city of Cimahi based on the written test is still relatively low.