THE EFFECT OF INQUIRY LEARNING MODEL TO STUDENTS' MATHEMATICAL PROBLEM SOLVING ABILITY IN GRADE X SMA NEGERI 1 PERBAUNGAN

The aim of this study is to determine and examine whether the Inquiry Learning Model effect the students’ mathematical problem solving ability in grade X SMA Negeri 1 Perbaungan. This study was quasi experimental with the Pre-test Post-test Control Group Design. The population of this research were all of students in grade X SMA Negeri 1 Perbaungan academic year 2018/2019. The sample of this research were taken by using random sampling technique, the sample only 72 students consisted of two classes, each class consists of 36 students. Class X MIA 2 was experiment class that taught by Inquiry Learning Model and class X MIA 3 was control class that taught by Direct Instruction. The data of the research were valid essay test of problem solving ability. The data were analyzed by using t-test at significant level α=5%. The result of this research shows that the average score of pre-test in experiment class X MIA 2 and control class X MIA 3 are 61,48 and 60,28. Then after doing treatment in both class obtained average score of post-test are 78,15 and 64,44. From the hypothesis testing tcount = 4,432 > ttable = 1,666, it means Ho rejected and Ha accepted. It shows that there is effect of Inquiry Learning Model to students’ mathematical problem solving ability