PENGARUH STRATEGI PEMBELAJARAN DAN KEMAMPUAN BERPIKIR LOGIS TERHADAP HASIL BELAJAR MATEMATIKA SISWA SD KOTA BINJAI

This aimed of this research were to : (1) the difference of achievement inmathematic between discovery learning strategy and expository learning strategy(2) the difference achievement of mathematic between students who had highlogical thinking and low logical thinking , (3) interaction between learningstrategy and logical thinking on the students achievement in mathematic.The population of this research was all five classes of SDN Negeri027962 and SD Gajah Mada Binjai, which consisted of five classes which had179 students all together. The sample of this research was four classes with 143students 2 classes wich 73 students taught by learning discovery strategy and2 classe wich 70 students done by learning of expository strategy. These samplewere taken by using cluster random sampling method. The research instrumentthat used the measure the achievement was test multiple choice with 4 option andreliability 0,84. To get of data logical thinking used of adaptation andmodification from Piaget . The research method used quasi-experiment withfactorial design 2 x 2. Technique of analyzing data used ANOVA of twodirections at significants α= 0.05.The finding of the research showed from 33 item test achievement ofmathematic showed that: (1) the students achievement in mathematic that taughtby discovery strategy ( X Al-23.16) is higher than the students achievement thattaught by expository strategy ( X A221.35), with Fratio = 12,22 > Ftable 3.92, (2) thestudents achievement in mathematic with high logical thinking ( X B1 23.88) ishigher than low logical thinking (5( B2 20.69), with Fratio = 42.35 > Ftable = 3.92,(3) be found interaction between learning strategy and the ability of logicalthinking on the students achievement in mathematic, with Fratio 82.45> Ftable3.92. The multiple comparation by Scheffe teste also showed significantdifference of achievement in mathematic between discovery strategy andexpository strategy, similar with achievement in mathematic between high logicalthinking and low logical thingking.