Computer educational games are among the strategies that activate the student and create creativity in them and not only improve the process of learning and student learning, but also lead to success in cognitive fields. The aim of the present study is applied and in terms of quasi-experimental method with pre-test, post-test and follow-up design. The fifth elementary ones were replaced by available sampling method in experimental and control groups. The experimental group was exposed to computer training in 30 sessions of 45 minutes during one month and the control group was trained in the traditional way. In this study, a mathematical competency test with a reliability coefficient of 87% was used to collect data. Research data were analyzed using SPSS software and statistical methods used in this study including descriptive statistics (percentage, mean, frequency, standard deviation) and inferential statistics (analysis of covariance, t-test, Kolmogorov-Smirnov test, regression slope). The results of the present study showed that computer training games on cognitive skills (F 1,37) = 92/64, p <0.01) and problem solving skills (F 1,37) = 12/37, p <0.02) 1 and the use of the five senses (F 34.1) = 21/83, p <0.01) and classification skills (F 1.37) = 18/88, p <0.01) and thinking skills (F 1,37) = 81.5, p <0.0, fifth grade elementary students have an effect on math lesson.