%A Muhsetyo Gatot %X The purpose of this study is describing the patterns of students work in area problems. The background of the study is students are still having difficulty in chosing the right strategy to find area. The method is developing “best practice”. The subjects are 17 students of mathematics education program . They come from different provinces of Indonesia. The best practice is done by (a) discussing the types of open strategies, and (b) working open-ended subjective test. The results gets the answer patterns . From problem one, there are nine students with right answers, and eight students with wrong answer. The patterns of right answers are six students work by combining parts, and three students work by subtracting the hole area by parts. The patterns of wrong answers are four students work by combining parts with mistake in calculation, three students make conceptual mistake, and one student work by subtracting the whole by parts with mistake in calculation. From problem two, there are eight students with right answer, and 11 students with wrong answer. The patterns of answers are combining parts, subtracting from the whole, using similarity, and applying Pythagorean Theorem. The fact shows that there is the growth of critical and creative of mathematical thingking.. Key Words: study, open-ended, area, work pattern. %L UNY23021 %T THE IMPLEMENTATION OF OPEN-ENDED APPROCH FOR IDENTIFYING STUDENT WORK PATTERNS ABOUT AREA CONCEPT %I Faculty of Mathematics and Sciences Yogyakarta State University %J Proceeding of International Conference On Research, Implementation And Education Of Mathematics And Sciences 2015 (ICRIEMS 2015), Yogyakarta State University, 17-19 May 2015 %D 2015