The following Work or Report that I present, was done using qualitative research where we were interested in recognizing the strategies of problem solving with and subtraction operations that the 6th grade students have. For this, we will show the existing problems regarding the learning of the Additive Structures (of the sum addition and subtraction subtraction). Emphasis was given to the interviews, discussion groups, observation, as well as descriptive research in which the characteristics of the issues and obstacles observed were described, the interviews, the responses of the different exercises, workshops and members' evaluations were analyzed. of the unit of work, the Resolution of mathematical problems was taken into account. It was tried to try to give possible solutions to the questions What is happening? What are the characteristics of the problems or obstacles presented? In the development of the Work, the development of the Work was treated and presented in eight stages or chapters, in chapter one it is talked about the Approach of the problem and the research question; in chapter two on Justification; in chapter three on the Objectives; in chapter four on the Theoretical Reference, which is composed of the Antecedents and the Theoretical Framework; in chapter five on the Methodology; in chapter six on the Results using Narrative, it is done using Narrative of personal type and Narrative on the process of teaching and learning; in chapter seven the Conclusions are made; in chapter eight the Recommendations are made and the bibliographical references are given.