The dim²ension project aims to integrate digital tools into mathematical modelling to address real-world problems, particularly those related to the United Nations' Sustainable Development Goals (SDGs). The project’s overarching objective is twofold: firstly, to enhance students' mathematical modelling competencies, and secondly, to foster awareness of global sustainability issues in schools. The present introductory chapter offers a comprehensive overview of the project, while also delineating the structure of the theoretical white paper.