Digital didactic units for mathematical strategy LEM: a step more for education and the effective learning in the school. 1º Stage and 2º Stage Project of Fondecyt Investigation: “To teach and to learn Mathematics in the Basic Education with support of TIC in classroom: A study of conditions for an effective incorporation of computer science surroundings to the processes of Education” 2008-2010 Project of Fonide Investigation: “Analysis of the mathematical competitions in first cycle. Characterization of the levels of complexity of the mathematical tasks” Project Strategy of Technical Attendance in Mathematical (2008-2012) Teaching in the University of Santiago Postítulo of mention in Mathematical Education for Professors of 2º Basic cycle of Education