The purpose of this paper is to focus on how the content of a single lesson that dealt with the addition and subtraction of negative numbers was handled in the interaction between students and a teacher in the 7th grade. The study is a follow‐up of a learning study and can be described as a teaching experiment. In total, four critical features for students’ learning were identified in the learning study.
In the new study, the teacher deliberately did not bring up all the critical features of the object of learning in one lesson. The aim was to see how different critical features made a difference for student learning.
The results show that a particular student's questions had an impact on the critical features that were brought up and hence on what it is possible to learn. In this lesson it was the students that opened some of the dimensions of variation for learning negative numbers.
The paper suggests that being aware of critical features could help the teacher in the interaction with the students and their questions.
