European policy documents highlight the importance of inquiry based learning (IBL). Norwegian whitepapers and curricula also strongly recommend and support the inquiry approach. The EU-project mascil (Mathematics and science for life) seeks to promote a widespread use of inquiry-based science teaching in primary and secondary schools across Europe. One major innovation in mascil is to connect IBL in school with the world of work, making science more meaningful for young European students and motivating their interest in careers in science. Through the participation in mascil, and by using the mascil approach, i.e. based on the cascade model and spiral model, we have educated in-service science and math teachers as multipliers in Norway. Having gone through the professional development (PD) courses with us, these multipliers are now arranging workshops for their colleagues, and thus a high number of teachers are involved. In this paper, we present experiences from multipliers. In particular, we look closely at how the multipliers have developed themselves in terms of their beliefs, efficacy and motivation in implementing the mascil’s ideas, and in spreading the ideas in the workshops with their colleagues. Based on case studies involving four multipliers, we found that the multipliers, despite their different background, have significantly benefitted from the PD-courses. Results from interviews, observations of workshop sessions and classroom lessons, show that they have become enthusiastic about implementing IBL and the world of work, and has proven to be capable of conducting lessons that inquiry-based and with close connection to the world of work. They have also become highly engaged in spreading the pedagogy to their colleagues in own school, resulting in fruitful development of teacher professional knowledge in their community of practice.