Upaya Peningkatan Kemampuan Berpikir Abstrak Matematika Dengan Media Visual Alat Peraga Pada Materi Geometri Bangun Ruang (PTK Pembelajaran Matematika Siswa Kelas X IPA 1 Semester Genap MAN Gondangrejo Karanganyar Tahun Ajaran 2014/2015)

The purpose of the study is to improve the ability of thinking abstractly of mathematics through visual media props on the materials of geometry of solids. This research is a Classroom Action Research. The recipient subject of the action is student X IPA 1 MAN Gondangrejo Karanganyar. There are 33 learners of the class which consists of 6 men and 27 women. The subjects of implementing action are the researcher and the mathematics teacher of class X IPA 1. The data are collected by using observation, test, fields note, documentation, and interview. The research belongs to descriptive qualitative research which encloses the data of reductions, the data of presentations, and drawing conclusion. The researcher applies triangulation in order to make the data valid. The results of the research show that improving of thinking abstractly of mathematics. These results can be seen from (1) learners in thinking carefully a number of different variables in the same time before the actions 12.12% and 69.69% after the action (2) learners in giving reasons appropriate with the concept before the actions 12.12 % and 57.57% after the action (3) learners in drawing conclusions dealing with the general rationale to explain specific things before the actions 15.15% and 63.63% after the action (4) the results of the test of learners’ ability has score s SCDT 15-22 before the actions 24.24% and 72.72% after the actions. It can be concluded that the media props can improve the ability of thinking abstractly of mathematics through visual media props on the material of geometry of solids