This chapter elaborates findings from a longitudinal ongoing cross-cultural study comparing the teacher education and classroom practices in Finland and Sweden. The focus is on the cultural scripts of mathematics instruction during the first school years (ages 6-8). Firstly, we present a description of the contexts of each country concerning primary teacher education and the transition from pre-school to school. We then characterize the dominating conceptualizations of the mathematics classroom practices for the early years in both countries, building on several analyses of different data sources. We focus especially on the intricate balance between flexibly building mathematics on pupils’ ideas of familiar everyday phenomena within a thematic teaching style on the one hand, and on the other, the organization of learning environments strictly based on a predetermined hypothetical learning trajectory (Clements & Sarama, 2007). Finally, we discuss our findings in light of the international literature on early mathematics education and transition from pre-school to school.