Ments to the conceptualization: the Zone of Development in Proximity (ZDP), as a symbolic space that has a semiotic aspect (that mediates meaning of language and symbols), as proposed by Meira and Lerman (2010). Such elements are derived from the analysis of an interdisciplinary piece of research carried out by two teacher-researchers one a mathematician, the other a scientist, both teaching the same year nine secondary class, at a public school in Belo Horizonte, Brazil. This analysis shows how, and under which circumstances, such interdisciplinary work challenges or encourages the students to "cross the boundaries" between the two disciplines. Based on two learning episodes, the notion of ZDP as a symbolic space is reinforced, and the fragility and instability of ZDPs are discussed.
Interdisciplinary; Cross-curricular; Zone of Development in Proximity; Language; Mathematics Education; Science Education