We are witnessing a great effort on the part of the educational systems of the world in modernizing the curricular content of primary and secondary schools. One example of these educational initiatives is the effort of integrating aspects of engineering and technology with the existing core subjects of sciences and mathematic in K-12 education. These efforts are often labeled as STEM or STEAM (Science, Technology, Engineering, Mathematics, and Arts.) These subjects, studied in an integral form, are considered essential in the education of the citizens of a modern society. A common obstacle encountered in the implementation of these projects or initiatives is the lack of consensus on the specific topics to be included in the curriculum, the pedagogical methodology selected for the classroom, and the means, computer-based or otherwise, to be used by the teachers and the students. Often the lack of consensus among the different constituencies in charge of these projects finds its roots in the different assumptions made by their participants. This paper addresses one of the most acute set of differences present in these projects: the teaching methods used in class, knowing the resources and limitations of the human mind. In the last few decades we have learned much of how the mind works; what tasks are intrinsically easy or difficult for the human mind. Also, with the extensive access to computing power in our society, it is important to determine if a traditional task was studied in school for its practical use or for its value in developing the potential qualities of the mind. In this paper we will use the word computation in its traditional meaning of symbol manipulation. In that sense, all processes of thinking, solving problems, and endeavors of creation are processes of symbol manipulation, or computation. In this paper we present a computational model of the mind in order to provide a standard reference that will help in finding answers to questions such as: when is a task complex, what are the cognitive capabilities and limitations of the mind, what teaching methodologies are optimal, and why.