The objective of this research was analyzing the propositions presented on didactic book of sixth year of the collection called The conquest of Mathematics for introducing the conceptof fraction based on Historical-cultural theory. The categories of analysis focus in three relations: discrete and continuous; arithmetic, algebraic and geometric significations; empirical and theoretical thinking. Research data were collected from Mathematic didactic book more used in the Public Network of Santa Catarina in the region of Tubarão. The propositions presented provide the concept of fraction in the limits of visual empiric, in other words, they do not achieve scientific abstraction of the concept of fraction from the study of magnitudes, not only discrete, but also continuous, algebraic and geometric. Thus, they do not reflect the principles from Historical-cultural theory.