While several countries have already introduced Computer Science or programming into their primary school curricula (e.g., the UK, Australia, or Finland), Germany has not yet developed mandatory guidelines on how to deal with these matters. Although there is an agreement that students of all ages should gain insight into the recognition and formulation of algorithms, the focus in primary school is often still on the mere use of computers. Programming courses, on the other hand, are increasingly found in extracurricular activities. It is still open to what extent and in what form algorithms and programming can and should be introduced in primary schools in the longer term. To help answer this question, we trained 40 primary school teachers in algorithms and programming and examined how they implement the topics in their individual schools. Among these are teachers who teach programming in class (formal learning) as well as teachers who offer their students extracurricular programming activities on a voluntary basis (non-formal learning). We interviewed all teachers about how they implemented the topics, what advantages they saw in the individual formats, and what challenges they encountered. In this paper, we outline our didactical approach as well as the results of our interview study.