Rocío Guadalupe Balderas Robledo, David Block Sevilla y María Teresa Guerra Ramos
Abstract: In this paper, we analyze the arguments that secondary teachers made about the presence or absence of proportionality in several written problems and, through these, we explore the explicit knowledge of the teachers about the properties that define proportionality. For the study we designed and administered a questionnaire to 63 practicing mathematics secondary teachers, we analyzed the procedures and some ideas about teaching the topic, as well as the characteristics attributed to proportional relationships. Most of teachers were successful in solving problems and some in the identification of proportionality. However, they showed a limited argumentation regarding the presence or absence of the proportionality; this is an indicator of the need for greater attention to these aspects during the initial and continuing training of teachers.
Keywords: proportionality, teacher’s knowledge, argumentation, secondary mathematics education.
