Abstract : The purpose of this thesis is to seek how men and women build alternative knowledge, when they are subjected to situations of social exclusion, in a peripheral community of the south of Brazil. Through a questionnaire applied on 103 subjects, 14 principal problems were identified whose solution supposes the construction of alternative knowledge. We analyzed three activities of work, developed in this context (mechanical turnery, seam and recycling of waste), and the role and function of the variable gender in the exercise of these activities considered in the community as masculine, female or neutral from the point of view of the gender. We still analyzed the implicit mathematical knowledge developed by these subjects in their work practices, and the common concepts of measurement between them. The theoretical framework calls upon the sociology of Castel and Paugam, the philosophy of the education of Freire, the philosophy of Foucault, and the psychology of development of Vergnaud. We called upon qualitative and quantitative methods for construction of the data with the questionnaire, the audio-visual recorded interviews both individual and collective. The results show that regarding the 14 studied problems (health, food, family, economy, marital status, work, education, insurance, leisure, religion, transport, sorting, dwelling, cleansing, relationship with vicinity) the subjects develop knowledge that seem to be maintained according to the contextual variables. One has observed different knowledge identified as concepts in action according to the theory of the conceptual fields of Vergnaud.