The present sufficiency work has been prepared for boys and girls of the second grade of primary education, of the city of Trujillo in the year 2019, with the theme entitled “we solve problems with additions with and without exchange”, in which it has been Keep in mind that students will be able to make additions without and with exchanges of units to tens using concrete material, where they will help develop different strategies for solving the problem through the representation in a concrete, graphic and symbolic way of natural numbers._x000D_ In the elaboration of the session we have worked with the pedagogical and didactic processes of the area of mathematics where they will promote in students to develop mathematical competences through a spiral process in which they expand the level of elaboration and depth of their knowledge, giving them increasing complexity and introduction ...