In the last two decades investigation of teachers' beliefs and conceptions and teachers' possibilities for change has been one of the points of emphasis in mathematics education. We propose the concept and design of an intervention program including five stakeholders on the basis of a teacher-student-parent-preservice teacher-teacher educator relation. The main idea is comprised of reversed roles in teaching and learning process i.e. elementary school preservice teachers should adopt beliefs and conceptions from the mathematically promising students (age 6-12). The program is defined by 10 relationships among stakeholders and was evaluated from various viewpoints. In this paper, we highlight the effect on the preservice teachers' competencies during the longitudinal study. We have focused on the gap between desired and achieved competences as viewed by the preservice teachers. Overall results speak in favour of presented approach.