Computational thinking (CT) has become central to introducing digital artefacts for educational use. However, little is known about implementing CT in the mathematical school curriculum, and many educational staff members have not been introduced to CT in their initial training. Introducing CT in an educational setting calls for interventions that allow educational staff to adopt new concepts and to explore ways of implementing CT and digital artefacts to support students' computational and mathematical understanding. This article focuses on formative interventions applied in the form of "Change Laboratory" to implement digital artefacts with a particular interest with regard to educational staff's expansive learning processes. To foster such expansive learning processes, double stimulation methods were introduced to enable educational staff to analyse and reflect on their work practices collectively. The research was conducted as an ethnographic intervention study in a primary school in Denmark. It began in 2019 and was completed in 2021. Participants were primary school students followed from 2nd grade to 3rd, alongside their math teacher and social educator. The data consisted of five Change Laboratory sessions fully transcribed from video recordings, including classroom activities between sessions. Through a Cultural Historical Activity Theory lens, the article concludes that by mapping educational staff's expansive learning actions, it is possible to identify how the participants collectively change their activities or not. Thus, analysing which phase of double stimulation that triggers a specific learning action provides knowledge about integrating CT and digital artefacts to support mathematical understanding.