In this report, I examine a part of the teaching of computer programming in a Swedish ”gymnasium”, carried out through the course ”Programmering A”. In this beginner course, students, often in heterogeneous groups, are taught the basics of using a programming language. However, quite a few pupils are facing problems in completing the course. Especially, the construction and use of ”for-loops” (in the programming language C++) seems to be hard to master. The report focus on the making and practising of a student-oriented excercise, which uses both visual and problem-oriented means to teach ”for-looping” in a way that makes learning easier, and also stimulates the students' creativity. Pros and cons with this excercise are discussed in the report, within the theoretical framework of the mathematician Papert and his ”constructionism”, as well as with some Swedish constructionist studies. The report is based on a qualitative study of three small student groups performing the excercise, at a ”gymnasium” in Sweden.