In this paper we discuss social creativity in a particular professional context, that of education. We studied how collaborative design of educational digital resources inspired social creativity and the influencing factors during this collaboration amongst a group of designers made up of mathematics teachers, teacher educators and researchers with diverse expertise. The research was carried out in the framework of the MC2 European project (http://www.mc2-project.eu/, 2013-2016) aiming to develop a socio-technical environment for the design of digital resources fostering creative mathematical thinking. Through the functional combination of theories, we conceptualize and study the social creativity that occurs during the collaborative design process of a digital resource embedding mathematics into a story. The methodology comprises two main stages, one for setting the context and the other for studying social creativity. We bring to the fore the importance of the moderation of the group of designers, the ignition of ideas, the use of designers' complementary knowledge and expertise, and the limitation of our communication tool.