Bachelor's thesis from 2013 in the field of Mathematics - Didactics, grade: 1.7, Bergische University Wuppertal, language: German. Abstract: Arithmetic is considered one of the fundamental prerequisites for a successful school career, alongside reading and writing. Lorenz and Radatz noted in 1993 in the Handbook of Supporting Mathematics Education that 6 percent of all elementary school students are extremely weak in arithmetic, and 15 percent show at least a need for support in this area. This raises the question of what can be done to counteract this percentage. To develop a fundamental understanding of arithmetic operations, mathematical competencies must be fostered as early as preschool age. This is precisely the topic I will address in this thesis.