Topics in learning mathematics are generally abstract in nature, while elementary school-age children think concretely. This makes a teacher must be able to manage learning mathematics well. The purpose of this study is to describe through concrete props in learning the material of the nets of simple space buildings can improve student learning outcomes. The method used is descriptive method with the form of research, namely classroom action research with 2 cycles. The research was conducted in class V at a elementary school in Hanoi City, Vietnam. The number of respondents consisted of 129 students consisting of 58 male students and 71 female students. Based on the first cycle, student learning completeness was only 37.21%. This achievement is classified as low. Based on reflection, cycle II made improvements in planning and in implementing learning. In cycle II there was an increase, where classical learning completeness became 96.89%. This shows that the use of concrete teaching aids in math learning can improve students' learning outcomes