The paper analyzes adult mathematics education from a cultural perspective. Specifically, its purpose is to broaden our comprehension about this field of knowledge using as a theoretical tool-box an Ethnomathematics perspective founded on post-modern thought, post-structuralism theorizations and Wittgenstein's work developed in his book "Philosophical Investigations." This Ethnomathematics perspective allows us to study the Eurocentric discourses that constitute academic mathematics and school mathematics; to analyze the effects of truth produced by the discourses of academic mathematics and school mathematics; to discuss issues of difference in mathematics education, considering the centrality of culture and the power relations that institute it; and to problematize the dichotomy between "high" culture and "low? culture in mathematics education. Taking elements of the empirical data produced in many years of fieldwork with peasants of the Brazilian Landless Movement who participate in adult education courses as students or as teachers, the paper discusses some aspects of this social movement, especially the educational work they are developing; it outlines the theoretical background that supports the idea that there are different mathematics; it presents and analyzes some elements of the mathematics produced by the Landless peasant form of life, establishing relations with school mathematics, problematizing curricular issues of adult mathematics education.