摘要：The difficulties presented by Brazilian students in the appropriation of the negative number reported in surveys contributed to the preparation of this article. Concerned about these difficulties, we turn to davydoviana proposition which is the subject of this study. The research problem is: what are the needs created in the particular tasks of davydovian educational organization for the introduction of the concept of negative numbers in school situation? It is a qualitative research method in the literature whose source analysis are four tasks present in the student textbook belonging to davydovian proposition. The review process was developed through necessity category: conceptual and pedagogical. The research shows that the need to study the negative numbers follows that only they enable the resolution of some cases of subtraction and equation. To provide the meaning of the opposite negative number, the main need is the passage from the scalar quantities to the vectorial. Keywords : Davydovian proposition. Negative numbers. Conceptual necessities. Normal 0 21 false false false PT-BR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Normal 0 21 false false false PT-BR X-NONE X-NONE
