RT journal article T1 The Open Algorithm Based on Numbers (ABN) Method: An Effective Instructional Approach to Domain-Specific Precursors of Arithmetic Development A1 Cerda, Gamal A1 Aragón Mendizábal, Estívaliz Lorena A1 Pérez, Carlos A1 Navarro Guzmán, Francisco José Ignacio A1 Aguilar Villagrán, Manuel A2 Psicología K1 domain-specific precursors K1 TEMA-3 K1 early arithmetic K1 ABN method K1 mathematics AB This article presents the results of a comparative study regarding the impact and contribution of two instructional approaches to formal and informal mathematical reasoning with two groups of Spanish students, aged four and five. Data indicated that for both age groups, children under the ABN method [Open Algorithm Based on Numbers (ABN)] (n = 147) achieved better results than the group under the CBC approach (Closed Algorithms Based on Ciphers) (n = 82), which is the widespread approach in Spanish schools to teach formal and informal mathematical reasoning. Furthermore, the comparative analyses showed that the effect is higher in the group of students who received more instruction on skills considered domain-specific predictors of later arithmetic performance. Statistically significant differences were found in 9 of the 10 dimensions evaluated by TEMA-3 (p < 0.01), as well as on estimation tasks in the number-line for the 5-year-old-group. However, the 4-year-old group only presented significant results in calculation and concepts tasks about informal mathematical reasoning. We discuss that these differences arise by differential exposure to specific number-sense tasks, since the groups proved to be equivalent in terms of receptive vocabulary, processing speed, and working memory. The educational consequences of these results were also analyzed. PB FRONTIERS MEDIA SA SN 1664-1078 YR 2018 FD 2018-09-25 LK http://hdl.handle.net/10498/30357 UL http://hdl.handle.net/10498/30357 LA eng DS Repositorio Institucional de la Universidad de Cádiz RD 12-nov-2026