Acquiring and mastering initial competencies in Natural Sciences is especially hard for urban students, as their personal experience concerning the domain is poor and contradictory. While the researchers emphasize the importance of hands-on experiments, inter-domain integration and real-life contexts, the design of a consistent framework for introducing students to Natural Sciences is still a challenge. Based on the Cultural-historical theory (Vygotsky) and the Developmental instruction (Davydov) we have designed an activity-based introductory Natural Sciences curriculum for 5th-graders and tested it in our previous studies. In our new pilot teaching project we adapted our materials to primary education to examine the earliest stages of initial competencies formation. The experimental class (20 students, 6-7 years old) had three lessons a week within their regular schedule. Classroom observations, students' materials, quizzes, tests, audio-taped classroom discussions, teacher’s diary were used as data source for qualitative analysis. In this paper a sample fragment on making bread is presented alongside with students’ works and discussion. The results are discussed in terms of “shifts” in formation of initial competencies, which we observed during the year. The formation of modelling (which we consider to be the central competency, based on our analysis) demands a thorough attention in future studies.