<p>The results of the diagnostic phase of a broader research are presented, which had the objective of strengthening metric thinking in seventh grade students through situations of the extracurricular context, since it could be evidenced that students only perform conversion processes, by neglecting the construction of the magnitude that is the object of the measurement and its comprehension; for this reason, a mixed analysis was carried out in order to understand what the student understands by measurement and to know the difficulties on the concepts associated with metric thinking. One of the results of the diagnostic test is students need to go deeper into the process of elaboration, comparison and exercise procedures, which is connected with communication, but it is also necessary to achieve better clarity about the mathematical object on which the student acts and the delimitation of the action that the student is going to perform on that object according to the purpose or goals to be achieved.</p>