"More than 20% of 15-year-old European students are low achievers in mathematics. Because low math competence can have dire economic and social effects, improving our knowledge of the neural mechanisms involved in arithmetic processing is critical to inform teaching and reduce low achievement. A central question in math education is whether calculation procedures should be emphasized over strategies based on retrieval during arithmetic learning. To date, studies suggest that calculation is less efficient than retrieval, at least for simple arithmetic problems. For example, problems for which subjects report using procedures are solved slower and less accurately than problems for which retrieval strategies are reported. Procedures are also linked to enhanced activity in fronto-parietal brain regions and this is thought to reflect effortful processing. These studies, however, might be misleading because (i) automatic procedures might be executed so fast that they cannot reach consciousness and (ii) enhanced activity in fronto-parietal regions during effortful calculation might not be related to procedures per se. This project will use functional magnetic resonance imaging (fMRI) to test the hypothesis that fronto-parietal regions may support automatized procedures that can be as efficient as retrieval. Specifically, we will capitalize on the idea that, in problems solved with procedural strategies, abstract automatic procedures should be pre-activated by the simple presentation of an arithmetic sign before the problem itself. First, we will test whether activity in fronto-parietal brain regions can be automatically triggered by the simple visual presentation of an addition sign, and whether this automatic activation may facilitate arithmetic performance in adults proficient in arithmetic. Second, we will investigate the behavioral and neural emergence of such automatic procedures during arithmetic learning in typically developing children (8-9 vs. 12-13 year olds)."