Our studies have enabled us to defend the theory that discussions on critical mathematical education (CME) are founded on theoretical elements which are present in Paulo Freire’s investigative concept of education. This article discusses some considerations about this concept. It is organized in a way that establishes a dialog between the author’s thinking in the contexts of literacy, the pedagogy of the oppressed, and the teaching of sciences. Finally, it discusses how to teach mathematics so that this teaching enables the development of a critical vision, in light of authors such as Skovsmose and D’Ámbrósio.