Starting with introductory chapters by key researchers in the area, the book brings forth chapters for each of the KOM framework’s eight mathematical competencies, authored by Nordic researchers in combination with international scholars. The KOM framework also operates with three types of overview and judgement, which are specifically addressed in relation to the role of digital technologies in the third part of the book. The fourth and final part of the book broadens the scene and provides chapters of a more perspective nature in relation to mathematical competencies in the digital era. The book’s preface is by Susanne Prediger.