Abstract :
Discussion method is one method of learning undertaken by teachers in learning activities to give students a problem to be solved togethers The formulation of the problem in this study is, Is there a difference learning achievement in mathemtics is taught by teaching methods discussion and methods expository on the subjek of sub square and rectangle semester of seventh grade students of smp negeri 20 kupang academic year 2014/2015? To addres this problem, recearches used quantitative with methods experiments in accordance with the objectives to be achived is to determine wheter there is a difference in learning in mathematics is taught by by teaching methods discussion and methods expository on the subjek of sub square and rectangle semester of seventh grade students of smp negeri 20 kupang academic year 2014/2015. The population in this study were all sevent grade students of SMP Negeri 20 Kupang City school year 2014/2015. The sample selection is done by random, ie researchers took two classes of the population to be samples, so taken classes VII D and VII B each sanple consisted of 30 students. Test requirements analysis used in this study is the homogeneity test using One?way ANOVA, testing normality using the Kolmogorov?smirnov test and the alkaline hypothesis test t test. Based on the analysis result obtained t independent samples test table shows sig.(2-tailed) = 0,000 by 4,576 and ttabel= 2,001717 with significance level 5% with dk=58. From the results of the manual count t = 4.58 > t table = 2.001717 so H0 is rejected and Ha accepted, it can concluded that there is a differences learning achievement in mathemtics is taught by teaching methods discussion and methods expository on the subjek of sub square and rectangle semester of seventh grade students of smp negeri 20 kupang academic year 2014/2015. Based on the above conclusions, the researchers advise that teachers can apply mathematic learning method of discussion, especially on the subject of sub square and rectangular.