By its nature, the learning of certain complex contents has always been a focus of attention and a challenge in the study of mathematics. This fact acquires greater importance if it is about the learning of children, because the psycho-cognitive skills of this type of user, especially when they attend the first levels of Basic General Education are not yet mature. As a result, children are unable to assimilate correctly and easily certain content of an abstract nature during the early stages of mathematics learning. This study presents the results of the application of a computer system called "Kinect based Augmented Reality Math Learning System - KARMLS", whose design and development uses the Augmented Reality technology and the motion sensor implemented in MS-Kinect camera. The developed application covers elementary math topics corresponding to the Basic General Education curriculum of the Republic of Ecuador. The study used an experimental quantitative approach, involving 29 third-grade children (13 girls and 16 boys), who attend to 2 Basic General Education schools in Riobamba city, Ecuador. The results that allowed to evaluate the prototype proposed in the study were obtained by means of a pretest and a posttest, which were contrasted with the students' t-test for paired samples. Through the analysis of data obtained and the discussion, it is concluded that the applied computer system had a positive effect for the learning when used as a supplementary tool in the classroom and that it was more effective in children who previously had low performance than with those of high performance. Also, the children were motivated and with positive attitudes regarding the use of the analyzed software.