Games Based Learning Module (GBLM) in this study has been designed and adapted by the researcher by referring to the National Pre-school Standard Curriculum (NPSC) and local context. The games were developed to test the effectiveness toward the mastery of number concepts and number operations comprehension. In this research, number concepts cover the skills of counting and comparing. Both these skills are basic mathematics that must be mastered by children before they could pursue advanced mathematics learning. Number operations include the skills of addition and subtraction. This research used quasi-experimental design with non-equivalent control group pretest/posttest research design. The experimental group consisted of 23 pre-school pupils while the control group comprised of 24 pre-school pupils. The experimental group used the GBLM module while the control group used the traditional methods. Research data was analyzed using SPANOVA (Split Plot ANOVA Test). The results show that there is significant main effect of pre-posttest and interaction effect of pre-post and group. The results also show that there is no significant main effect of group.