Applying the theory of construct in general teaching, teaching math in particular will contribute to develop the capacity to learn and improve teaching effectiveness. Through learning activities, pupils construct knowledge themselves under the direction and orientation of teachers. In particular, for the end of primary school classes (grades 4, 5), the training for pupils having creativity, collaboration capabilities, the ability to self-learning, self-study,... is necessary. For this reason, the authors propose a number of measures to contribute to improving the effectiveness of teaching math at the end of primary school classes base on construct theory.