### Abstract

The teacher's knowledge of the mathematical fidelity of technology and the impact it has on the teacher’s practice is the focus of this article. Based on the conceptualization of Knowledge for Teaching Mathematics with Technology (KTMT), and involving the teaching of Functions at the 10th grade, we analyze: the situations of lack of mathematical fidelity considered by the teacher in the classes, the way how the teacher manages students' contact with this kind of situations, and how the teacher supports students when they are faced with a lack of mathematical fidelity. The conclusions reached point to: some devaluation of the situations of lack of mathematical fidelity, with only one type of situation being explicitly addressed; a careful selection of tasks, in order to ensure that these situations do not occur too soon; a focus on the identification by the students of this type of situation, suggesting what they can do to confirm the suspicion but without effective implementation of the process. As a consequence, knowledge of mathematical fidelity does not necessarily have a relevant impact on teacher’s practice and it is not easily transformed into a deep teacher’s KTMT.

Original language | Portuguese |
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Title of host publication | Atas do XXVIII Seminário de Investigação em Educação Matemática |

Pages | 116-128 |

Publication status | Published - 2017 |

## Cite this

Rocha, H. (2017). O professor e a fidelidade matemática da calculadora gráfica no estudo de funções. In

*Atas do XXVIII Seminário de Investigação em Educação Matemática*(pp. 116-128)