Sharing ideas, stories and narratives through videos on social media, is becoming a habit for people all over the world. The narratives communicated through this media are enriched with a combination of semiotic resources; language, images, symbols, and gestures, among others, making them more attractive to their target audience. Access to social media from mobile devices makes it possible for narratives to be watched anywhere, at any time. In this chapter, we present studies that have investigated the use social media and discuss the case of the YouTube channel created by a research group linked to a Brazilian public university. This interactive channel has been used to disseminate mathematical ideas in two strands. In the first strand, the narratives echo the voices of collectives of students and teachers from primary and higher education, people from the community, and more recently, native and traditional peoples. This has been organised in successive festivals of digital videos and mathematics education. In a second strand, the narratives have an academic language, consisting of interviews, lectures, and live streams (known as ‘lives’), in which mathematics and digital technologies permeate discussions on various topics, such as democracy, justice and social equity, among others.