In our Computing with Emil project, currently in its 4th year, we are engaged in the design and research focused on productive constructionist learning of programming at the primary level, as a continuum from year to year. We are exclusively concerned with computing for all learners approach, being implemented by generalist primary teachers in their own classes. For similar purposes, national curricula usually list computational concepts, which pupils should learn and, in general agreement among educational experts, are considered developmentally appropriate for the primary school. However, in our work, we feel the vocabulary being normally used for this is too coarse-grained to clearly specify the learning goals, especially in the area of programming. Therefore, for each computational concept, we try to identify a set of related operations that primary pupils should learn in any particular year. In this research, we tried to verify whether our approach is comprehensible for teachers and prolific in outcomes for their pupils. We wanted to find out whether they realise that (a) different operations performed with each concept have different cognitive demands, and (b) these demands determine the arrangement of activities in an intervention. We addressed a large group of teachers who had already participated in our professional development sessions on the intervention for Year 3. We chose repetition as one of the concepts and designed six assessment tasks focused on various operations that pupils perform with it. We did not inform them of how we rank the tasks; we asked them to solve them and rank from the simplest to the most difficult, and explain their decision. We analysed the collected data by various methods, and in the paper, we discuss our findings. Teachers correctly distinguished different operations and helped us better understand challenges of projecting and assessing conceptual understanding.