ABSTRAK
Tujuan penelitian ini yaitu: (1) mendeskripsikan langkah-langkah penerapan model Think Talk Write (TTW)dengan media bangun datar; (2) meningkatkan pembelajaran matematika tentang sifat-sifat bangun datar siswa kelas V SDN 2 Jatisari tahun ajaran 2014/2015; dan (3) mendeskripsikan kendala dan solusi penerapanmodel Think Talk Write (TTW) dengan media bangun datar dalam pembelajaran matematika.
Penelitian ini merupakan Penelitian Tindakan Kelas (PTK) kolaboratif. Penelitian ini dilaksanakan dalam  tiga siklus, tiap siklus terdiri dari perencanaan, pelaksanaan, pengamatan, dan refleksi. Subjek penelitian ini adalah siswa kelas V SDN 2 Jatisari tahun ajaran 2014/2015 yang berjumlah 29 siswa yang terdiri dari 18 siswa laki-laki dan 11 siswa perempuan. Validitas data menggunakan teknik triangulasi yang berupa triangulasi sumber data dan teknik pengumpulan data. Sumber data dalam penelitian ini terdiri dari guru, siswa, dan observer. Teknik pengumpulan data yang digunakan yaitu tes, observasi, dan wawancara.
Hasil penelitian menunjukkan bahwa: (1) penerapan model Think Talk Write (TTW) dengan media bangun datar dilaksanakan melalui empat langkah, yaitu: (a) menjelaskan materi; (b) membagikan LKS; (c) think; (d) membentuk kelompok;(e) talk; (f) write; (g) mempresentasikan hasi diskusi; (penutup, (2) penerapan model Think Talk Write (TTW) dengan media bangun datar dapat meningkatkan pembelajaran matematika tentang sifat-sifat bangun datar di kelas V. Hal ini ditunjukkan dengan adanya peningkatan ketuntasan pembelajaran pada tiap-tiap siklus yang mencapai KKM =75. Persentase ketuntasan pembelajaran  pada siklus I mencapai 62,07%, siklus II mencapai 85% dan siklus III mencapai89,66%; dan (3) kendala penerapan model pembelajaran Think Talk Write (TTW) dengan media bangun datar yaitu: (a) siswa kurang memanfaatkan kesempatan untuk bertanya pada guru tentang hal-hal yang belum dipahami; (b) pemberian motivasi masih kurang.  Solusi untuk mengatasi kendala tersebut yaitu: (a) mendorong siswa agar memanfaatkan  kesempatan dengan baik untuk bertanya pada guru tentang hal-hal yang belum dipahami; (b) guru menambah motivasi kepada siswa.
Kesimpulan penelitian ini adalah penerapan model pembelajaran Think Talk Write (TTW) dengan media bangun datar dapat meningkatkan pembelajaran matematika tentang sifat-sifat bangun datar pada siswa kelas V SDN 2 Jatisari tahun ajaran 2014/2015.    
Kata kunci: TTW, Media Bangun Datar, Pembelajaran, Matematika
ABSTRACT
The objectives of this research are: (1) to describe the steps in the implementation of Think Talk Write (TTW) model using two-dimensional shape in improving Mathematics learning; (2) to improve Mathematics learning about characteristics of two-dimensional shape for the fifth grade students of SDN 2 Jatisari in the academic year of 2014/2015; and (3) to describe problems and solutions in the implementation of Think Talk Write (TTW) model using two-dimensional shape in Mathematics learning.
This research is a collaborative Classroom Action Research (CAR). This research was conducted in three cycles, every cycle consists of planning, implementation, observation, and reflection. The subjects of this research are fifth grade students of SDN 2 Jatisari in the academic year of 2014/2015, totalling 29 students consisting of 18 male students and 11 female students. The validity of data used triangulation technique in the form of triangulation of data sources and data collecting technique. Data sources in this research were obtained from teacher, students, and observers. Data collecting technique were test, observation, and interview.
The results of this research show that: (1) the implementation of Think Talk Write (TTW) model using two-dimensional shape has been carried out through four steps, namely: (a) convey teaching; (b) division LKS ; (c) think; (d) the division of the group; (e) talk; (f) write; (g) presentation result discussion; (h) closing. (2) the implementation of Think Talk Write (TTW) model using two-dimensional shape that was implemented based on its steps can improve Mathematics learning about characteristics of two-dimensional shape in the fifth grade of elementary school. This is showed by the increase of learning success in every cycle which achieved minimum grade criteria more than 75. The percentage of learning outcomes in cycle I achieved 62.07%, in cycle II increased to 85%, and in cycle III increased to 89.66%; and (3) the problems of the implementation of Think Talk Write (TTW) model using two-dimensional shape namely: (a) students took less the opportunity to ask the teacher about things that are not yet understood; (b) less giving motivation. The solution to overcome that problems namely: (a) encourage student to take advantage of the opportunity well to ask the teacher about things that are not yet understood; (b) teacher encourage motivation to student.
The conclusion of this research is the implementation of Think Talk Write (TTW) model using two-dimensional shape can improve Mathematics learning for the fifth grade students of SDN 2 Jatisari in the academic year of 2014/2015.
Keywords: TTW, two-dimensional shape, learning, Mathematics