IMPROVING SENIOR HIGH SCHOOLS STUDENTS’ MATHEMATICAL CREATIVE THINKING ABILITIES THROUGH THINK-TALK-WRITE (TTW) COOPERATIVE LEARNING Wahyu Hidayat Mathematics Education Major, STKIP Siliwangi Bandung, West Java, Indonesia azzam@wahyurock.com Abstract This research is a form of quasi-experimental pretest-posttest in controlling group, which is using both of the cooperative learning approach of Think-Talk-Write (TTW) and the conventional learning. The samples are taken in two classes from the eleventh grade on one of senior high schools in Cimahi. The experimental class learns in Cooperative TTW learning, and the control class learns in a conventional manner. The samples involve about 63 students. Instruments is used include the test on mathematical creative thinking abilities. The analysis of data is using two way ANOVA, followed by Scheffe test. Based on the results of data analysis, it is concluded that: (1) The improvement of mathematical creative thinking abilities of students who received cooperative learning with Think-Talk- Write (TTW) is better than the students who received the conventional way of learning based on the students' ability levels of high, medium, and less (= 5%), (2) There is no interaction effect between learning approaches and TKAS (Tingkat Kemampuan Awal Siswa = Students’ Initial Ability Level) in generating creative thinking mathematics abilities of students, (3) learning approach factors have a greater role in improving mathematical creative thinking abilities compared to TKAS. Keywords: mathematical creative thinking, Think-Talk-Write (TTW) I. INTRODUCTION 1.1. Background Mathematic, a universal science underlying the development of modern technology plays important role in various disciplines and the advance of human intellectual. Mathematic learning given at every level of elementary and secondary education aims at enabling students to use mathematics as a way of reasoning (thingking logically, analytically, systematically, critically, creatively,