Berdasarkan pengalaman peneliti mengajar di kelas VII khususnya VII-A SMP Negeri 2 Patean, selama ini guru jarang melakukan variasi pada pembelajaran di kelas dan kurang memberikan tantangan kepada siswa bahkan belum pernah menerapkan pembelajaran pemecahan masalah dengan pendekatan saintifik. Permasalahan dalam penelitian ini, apakah pembelajaran Pemecahan Masalah dengan Pendekatan Saintifik dapat meningkat kan kemampuan berpikir kreatif matematik dan prestasi belajar siswa pada materi banguri datar segiempat bagi siswa kelas VII-A.Untuk membahas permasalahan di atas, maka dilakukan penelitian tindakan kelas yang dilaksanakan dalam 2 (dua) siklus, masing-masing terdin dari perencanaan, pelaksanaan, pengamatan, dan refleksi. Pengumpulan data dilakukan melalui kegiatan observasi, wawancara, dan tes akhir siklus. Subjek penelitian adalah siswa kelas VII-A SMP Negeri 2 Patean yang berjumlah 25 siswa dengan komposisi 13 siswa putra dan 12 siswa putri. Indikator dalam penelitian ini adalah (1) Kemampuan berpikir kreatif matematik siswa rata-rata minimal pada kategori cukup kreatif, (2) Sekurang- kurangnya lebih dari 75% siswa kemampuan berpikir kreatif matematik termasuk kategori cukup kreatif, (3) Prestasi belajar siswa rata-rata mencapai batas minimal KKM yaitu 70, (4) Sekurang-kurangnya lebih dari 75% siswa prestasi belajarnya mencapai batas minimal KKM yaitu 70. Pada kondisi awal (pra-siklus) kemampuan berpikir kreatif matematik siswa dengan level sangat kreatif 0 siswa (0%), kreatif 2 siswa (8%), cukup kreatif 6 siswa (24%), kurang kreatif 8 siswa (32%), dan tidak kreatif 9 siswa (36%). Pada siklus I terjadi peningkatan kemampuan berpikir kreatif matematik siswa level sangat kreatif 1 siswa (4%), kreatif 7 siswa (28%), cukup kreatif 9 siswa (36%), kurang kreatif 5 siswa (20%), dan tidak kreatif 3 siswa (12%). Pada siklus II lebih meningkat, siswa dengan kemampuan berpikir kreatif matematik level sangat kreatif 2 siswa (8%), level kreatif 9 siswa (36%), cukup kreatif 9 siswa (36%), kurang kreatif 3 siswa (12%), dan tidak kreatif 2 siswa (8%). Pada Siklus II banyak siswa dengan kemampuan berpikir kreatif matematika minimal level cukup kreatif ada 20 siswa (80%). Pada kondisi awal (pra-siklus) nilai tertinggi prestasi belajar siswa 80, nilai terendah 40, rata-rata nilai 60, dan ketuntasan klasikal 32% atau hanya 8 siswa yang mampu mencapai nilai di atas KKM 70. Pada Siklus I, nilai tertinggi prestasi belajar siswa 90, nilai terendah 45, dengan rata-rata nilai 68, dan ketuntasan klasikal 68% atau hanya 17 siswa yang mampu mencapai nilai di atas KKM 70. Sehingga masih ada 8 siswa atau 32% yang nilai prestasi belajarnya di bawah KKM. Pada siklus II meningkat menjadi nilai tertinggi prestasi belajar siswa 95, nilai terendah 50, dengan rata-rata nilai 75, dan ketuntasan klasikal 80% atau 20 siswa telah mampu mencapai nilai di atas KKM 70 namun masih ada 5 siswa atau 20% yang nilai prestasi belajarnya di bawah KKM. Dari hasil penelitian diperoleh bahwa penerapan pembelajaran pemecahan masalah dengan Pendekatan Saintifik dapat meningkatkan kemampuan berpikir kreatif matematik dan prestasi belajar siswa.
Kata kunci: kemampuan berpikir kreatif matematik, pembelajaran pemecahan masalah dengan pendekatan saintifik, prestasi belajar

Based on the teaching's experience in class VII especially VII-A of SMP Negeri 2 Patean, the teacher realizes that he rarely does variations on learning in the classroom and less provides a challenge to the students. Even he never applies a problem solving on learning- teaching activity with scientific approach. The research was conducted by asking whether a problem solving with scientific approach can improve creative mathematical thinking skills and students' achievement on a flat rectangular (bangun datar segiempat) materials for students of VII-A. To solve the above problems, the study of the Class Action Research (CAR) was conducted. It was devided in two (2) cycles, each consisting of planning, acting, observing, and reflecting. The data were collected through observation, interviews, and a final test cycle. The subjects were students of class VII-A SMP 2 Patean totaling 25 students with the composition of 13 boys and 12 girls. The indicators of this study were (1) the average of student's ability to think creatively mathematics on the category of creative enough, (2) more than 75% of students have the ability to think creatively mathematics, including on the category of creative enough, (3) the average of students' achievement can reach the minimum passing grade or KKM that is 70, (4) more than 75% of students can reach KKM. At the pre-cycle, students' ability to think creatively were very creative level 0 students (0%), creative 2 students (8%), quite creative 6 students (24%), lack of creativity 8 students (32%), and uncreative 9 students (36%). In the first cycle an increase in the ability of students' creative thinking very creative level 1 students (4%), creative 7 students (28%), quite creative 9 students (36%), lack of creativity to 5 students (20%), and not creative 3 students (12%). In the second cycle is increased, the students with the ability to think creatively: Very creative 2 students (8%), creative 9 students (36%), quite creative 9 students (36%), less creative 3 students (12%), and uncreative 2 students (8%). In the second cycle students with the ability to think creatively minimum level mathematics creative enough there were 20 students (80%). At pre-cycle the highest student achievement was 80, the lowest was 40, the average 60, and 32% or only 8 students were able to achieve the above KKM that is 70. In the first cycle, the highest students' achievement was 90, the lowest achievement was 45, the average achievement was 68, and the mastery learning was 68% or only 17 students were able to achieve the KKM. So, there are 8 students or 32% the KKM. In the second cycle, the highest value of student achievement was 95, the lowest achievement was 50, the average achievement was 75, and 80% or 20 students were able to reach above the KKM 70 but still there was 5 students (20%) were under the KKM. The result showed that the application of learning with Problem Solving based on a Scientific Approach can improve creative thinking skills of mathematics and student achievement.
Keywords: creative thinking ability of mathematics, learning achievement, problem solving based on a scientific approach