The present research contrasts the effect of the presence or absence of a module of selfefficacy in a hypermedia, on the achievement of learning as a solution to problems with fractional numbers. The interaction between the variable of learning achievement, and the cognitive styles of students in the dimension of the dependence – independence field was examined. Fifty (50) students participated in two courses which previously constituted fifth grade primary school education at a public institution in Soacha (Cundinamarca - Colombia). With regards to data processing, an Ancova analysis was done, which showed significant and positive effects on the learning achievement through the presence of the self-efficacy module. Moreover, it was evinced that the differences of achievement among the students of distinct cognitive styles disappeared.