This paper resulted from an unfolding of an ongoing doctoral research that deals with the characterization of a specific type of arithmetic in times of Brazilian industrial education, that is, between 1942 and 1968. The objective is to analyze knowledge produced by Roberto Mange for training, aiming not only to recognize them as such, but also to situate the social place of the producing agent, Roberto Mange, an "expert" in industrial education. The concepts mobilized are in line with the studies by Hofstetter, Schneuwly and Freymond (2017), and the methodological guidelines of Morais (2020). The research reveals that Roberto Mange introduced in Brazil new ways of teaching Mathematics, using the Occupational Methodological Series, the Instruction Sheets, and the Individualized Instruction Method. The conclusion is that Roberto Mange is an "expert" in industrial education.