**1. Introduction**

As mathematics plays an important role in the world, mathematical literacy represents a central objective in education. For the fulfillment, mathematical literacy standards in mathematics or minimum requirements have been developed in many countries (for example, see [1]) and substantiated in the curricula.

Those formulated objectives are to be applied for learners of all levels of abilities, for high achievers as well as for low achievers, so they have to be implemented in inclusive classrooms [2]. For successful inclusive settings, differentiation is of major importance, allowing individual learning processes as well as common learning situations and interactions. To ensure that also low achievers have the greatest possible chance for content related interaction, the acquisition of basic competencies is central.

This article will first address the role of basic competencies in elementary mathematics, concretized for the topic of place value (Section 2). In the following, the project "MaCo", focusing especially on fostering mathematical basic competencies, will be sketched (Section 3). It will be illustrated that the project addresses both teachers' as well as students' level. Furthermore, selected developed materials for the module "understanding of place value" will be presented (Section 4). Finally, conclusions and perspectives for inclusive mathematics are given—addressing the students' as well as the teachers' level (Section 5).
