Current mathematics education requires that teachers in this field challenge the characteristics of traditional education and reflect on the attitudes of their work, inducing them to innovate in order to transform the learning process. The instructional strategies and pedagogical tools used by teachers become ways to develop mathematical skills in situations where the use of errors is presented as a viable alternative for learning in the resolution of mathematical problems. The objective of the present study is to characterize the errors presented by students when solving mathematical problems, for which it is necessary to build an instrument which applies the criteria of validity and reliability, then a group of key informants selected by the researcher's criteria develop the instrument, in order to determine the errors presented by the students, where the methodology applied for the research is qualitative within the phenomenological nature. The errors presented are contrasted with the Radatz and Soccas categories, evidencing in the students the five categorized errors. Thus concluding that the most outstanding error is the one that evidences weakness in the previous concepts for the development of the problematic situations, in addition to highlighting the incorrect handling of mathematical algorithms, ignorance of symbols and fundamental mathematical concepts.