THE DIFFERENCE OF MATHEMATICAL PROBLEM SOLVING ABILITY BY USING STUDENT TEAMS ACHIEVEMENT DIVISION (STAD) AND DIRECT INSTRUCTION (DI) ON SYSTEM LINEAR EQUATION TWO VARIABLE IN GRADE VIII SMP NEGERI 11 MEDAN ACADEMIC YEAR 2013/2014

Objective of this study is to know whether mathematical problem solving ability by STAD higher than mathematical problem solving by DI on Linier Equation. The type of research which is used in this study is Quasi Experimental Research with Pretest and Posttest with two experiment class. Population of this study is all of the student in VIII grade of SMP Negeri 11 Medan. They are experiment class (VIII-9) taught with STAD and experiment class II (control class) (VIII-8) taught with DI model. The instrument that arranged have legalized by expert validator namely lecture and teacher mathematics. Hypothesis test method that is used is independent sample t-test. Result of this study at α = 0.05 shown that taccount > ttable namely 3.75 > 1.675. it means that students mathematics problem solving ability by STAD higher than mathematical problem solving by DI on Linier equation two variable system for VIII grade in SMP Negeri 11 Medan.