This article presents a number of carefully selected activities for the mathematics classroom in the early grades. The motivation for their selection is the development of concepts rather than the learning of the procedural skills of arithmetic. As the teacher is faced with a great heterogeneity of children starting school, the concrete learning environment should fulfil several requirements. On the one hand, the environment has to represent core mathematical principles, and, on the other hand, they have to be suitable for all learners in an inclusive classroom. The concrete formats themselves serve a specific conceptual purpose, while, at the same time, addressing, in an integrated way, the needs of a variety of learners with different levels of competence.