THE ABILITY OF MATHEMATICAL COMMUNICATION OF JUNIOR HIGH SCHOOL STUDENTS IN SOLVING OPEN-ENDED PROBLEMS GRAPHICS FUNCTION

The ability of mathematical communication is the skill to communicate mathematics that is learned and the skill of using mathematics as a communication tool (mathematical language). Mathematical communication skills are very necessary in learning. Without mathematical communication skills, a person will not be able to deliver statements according to their desire. This qualitative descriptive study aims to describe the level of mathematical communication ability of junior high school students in solving open ended problems with the topic of functional graphs. The method of collecting data through written tests and interviews. Written tests were given to 115 8th grade students of junior high schools in Surabaya, followed by interviews of one student at each level of mathematical communication ability. The results showed 51 people (44%) were at fourth level, 27 people (24%) at third level, 23 people (20%) at second level, and 14 people (12%) at first level. Students at fourth level and third level are equally able to use mathematical language that was accurate and effective, and appropriate in providing the strategies. But it was different in giving the arguments. Students at second level can not provide logical arguments, the mathematical language used was less effective and accurate, and the strategies used were precise but incomplete. Students at first level did not provide the right strategies because the lack of information which contained in the story, did not provide responses more to the stories they have been written, and did not demonstrate the ability to use mathematical language that was  accurate and effective.