The study of math achievement is fundamental. Its importance lies in analyzing what variables affect a significant percentage of students is not to reach their basic standards. In this sense, the contextual variables may become decisive. The purpose is to analyze data obtained after administration to a sample of students of an evaluation tool that measures mathematical competence. The data were analyzed from two contextual variables, ownership and environment centres, demonstrating statistically significant differences. The evaluation of the students should develop in all its scope, adequately considering the competences and the contextual elements that may influence their results.