In this study we analyzed the discursive actions employed by low-achieving students when they used an interactive technological artifact that simulates a two-pan balance scale to learn about mathematical equality. The study was guided by the commognition framework. Three pairs of low-achieving 16-year-old students participated in this study, in which they were asked to use the artifact to compare mathematical expressions. The results indicate that the commognitive processes exploited by students as they learned the mathematical equality-inequality were reflected in the evolution of their discourse. This evolution was present in the sequence of routines, with which the students were engaged. This routine evolution advanced from everyday discourse into mathematical discourse. The routines’ evolution was guided by the teacher, and therefore, we conclude that the combination of the potentials of the artifact together with the teacher’s actions helped students understand the mathematical equality-inequality.