Juscileide Castro et al. 2020. Island of Operations: a digital educational resource with multiple representations for understanding the additive field. In Workshops Proceedings of the 9th Brazilian Congress on Computers in Education, November 24, 2020, Online, Brasil. SBC, Porto Alegre, Brasil, 108-115. DOI: https://doi.org/10.5753/cbie.wcbie.2020.108.