This work integrates a research on what mathematics must be taught at the Adult High School in Argentina? The results of an exploration of the utility of mathematics and its teaching at Adult High School from student's viewpoint are presented. The results of five focus groups with adult students are explored as a supply for a survey. The data are analysed with a qualitative technique based on an inductive categorical and another lexical-metric. The results show that the students attribute little utility to the studied mathematical knowledge, existing a long distance between the mathematics teaching in the Adult High School and its goal of learning for life. The contribution of both analyses to this type of research is discussed.