Silva Filho, O.L. da, Ferreira, M. e Nogueira, D.X.P. 2020. The abacus in the inquire-based learning of addition and subtraction. Plurais - Revista Multidisciplinar. 5, 2 (ago. 2020), 22–39. DOI:https://doi.org/10.29378/plurais.2447-9373.2020.v5.n2.22-39.