Using the archives of the Federal Institute of Education, Science and Technology of Southern Minas Gerais - Inconfidentes Campus as a source, we sought to understand the teaching of maths in the first agricultural schools, as well as identifying the content taught to the boys at the 'Visconde de Mauá' Agricultural Apprenticeship in the 1940s and 1950s. For this study, we used reports issued by the Superintendence of Agricultural and Veterinary Education (SEAV), which was responsible for the agricultural schools at the time, teachers' reports, school reports on the activities carried out at the school and administrative files of staff and teachers at the Visconde de Mauá Agricultural School, which describe the institution's organisational structure, as well as physical and material issues and teachers' perceptions of the classroom. The documents covered the period in question show situations such as the multiple subjects taught by the same teacher, the organisational problems and pedagogical issues at the Escola Agrícola.