Os números inteiros durante matemática moderna nas escolas técnicas em Portugal

Between 1950 and 1970, the modern mathematics movement spread worldwide and integrated profound changes in the discipline's curriculum, associated with alterations in teaching methodologies and school mathematics practices. In this text, we will analyse how the whole numbers and their operations are approached in the first year of industrial courses in Portugal during the reform. We review documentary sources such as journals, school manuals, legislation, and other references contributing to a vision of teaching practices in technical schools. To present integers and their operations, the notion of vector was used, giving a new structure to the mathematical discipline of the 1st year of industrial courses but preserving the importance of applications in the real world.