The essay presents the results of a survey aimed at evaluating how the time variable influences the performance of Invalsi math tests in the Italian secondary school. It is worth to say that these tests are intended to detect not specific knowledge or skills but how students can use what he/she has learnt in order to solve new problems. The survey wants to find out in which terms the time available variable influences a different expression of competences. Indeed it offers a pedagogical-didactic interpretation space that gives qualitative and not just quantitative meaning to results.