THE DIFFERENCE IN IMPROVING STUDENTS' MATHEMATICS UNDERSTANDING AND ABILITY OF VISUAL THINKING BY USING COOPERATIVE LEARNING MODEL TYPES THINKING PAIR SHARED (TPS) AND NUMBER HEAD TOGETHER (NHT)AT SDN PERCOBAAN MEDAN

The purpose of this research is to describe: (1) the difference of improvement of students' mathematical reasoning ability which is learned by using cooperative learning type think pair share (TPS) and number head together (NHT), (2) difference of visual thinking ability of students using cooperative learning model of TPS and NHT type, (3) student's answer process in solving problems related to mathematical reasoning ability after obtaining cooperative learning of TPS type compared with NHT learning, (4) student's answer process in solving problems related to visual thinking ability after obtaining cooperative learning type of TPS compared with NHT learning. This study is a quasiexperimental study. The population in this research is class IV SDN Percobaan Medan Baru consisting of 2 classes that is class IVa and IVb which each class amounted to 32 people, so the research population amounted to 64 people. The sample was taken using purposive sampling method or also known as sampling consideration of 2 classes. Data analysis was done by inferential analysis. The results of this study indicate that (1) there is a significant difference in improvement between students' mathematical reasoning abilities taught through the TPS and NHT learning model, (2) There is a significant difference of improvement between Visual Thinking students taught through TPS and NHT models, (3) Student response measures on the reasoning skill tests according to the indicators make the allegations and the proof-maker of the reasoning skills test obtained that the correct answer for the NHT class is 22 more students than the TPS class as many as 15 students, (4) Student response measures on the test of visual thinking ability especially aspects of painting,
drawing or plagiarize the geometry between students who were given NHT learning better than students who were given NHT learning.