Between 2013 and 2018, the Brazilian National Textbook Program evaluated and distributed mathematics textbooks for the countryside population in Brazil. We analysed ten textbooks of this program. From a Foucaultian perspective, textbooks can be conceived as a power technology for governing population to make them types of people. Through a discourse analysis, two statements in the textbooks were identified: the peasant lives an idyllic lifestyle and mathematics supports that life; and the peasant must use mathematics to change the traditional lifestyle into a modernized and effective form of life. Textbooks use images and contexts of traditional countryside lifestyle to present mathematical activities. School mathematics, as articulated in the textbooks, plays an important role in peasant subjectivation processes, being a powerful tool of validation for the need to adopt modern production. Therefore, the notion of citizenship in the countryside context embodies practices to bring solutions to local and global problems, feeding the individual with responsibilities in governing one through the good and better path for himself, his family, his community and his world. The notion of a modernized peasant-citizen is built through the connection between local knowledge and practices, reorganized by mathematical tools and arguments to connect with modernized, global productive practices.