Validation d'une version française du NADL-F : mesure de l'impact dans l’utilisation financière au quotidien chez des adultes avec des difficultés en mathématiques.

Context: Mathematical skills are essential, since mathematics is ubiquitous in industrialized countries. Mathematical difficulties persist into adulthood in people with Mathematical Learning Disabilities, formerly known as dyscalculia. Yet few studies have focused on this population, and none have measured the impact of such disorders on everyday financial skills. Aim: The aim was to investigate whether adults with mathematical difficulties have more difficulty than adults without mathematical difficulties in manipulating financial concepts and understanding purchasing situations. Method: The present study included 171 volunteers with no acquired neurological disorder. Thus, 63 adults with mathematical difficulties and 108 control participants were compared on financial tasks derived from the Italian NADL-F test (Arcara, 2017) translated and adapted into French (NADL-F-fr) for the present study: counting change, reading numbers on financial supports, paying or giving change in purchase situations, calculating percentages, defining financial terms, spotting scams. Participants also gave feedback on their skills in these areas. Results: The performance of adults with mathematical difficulties is consistent with their perception of their difficulties. They perform significantly less well at counting change, reading numbers on financial or commercial documents, estimating the amount of their shopping, calculating percentages and defining financial concepts. Conclusion: Adults with mathematical difficulties also have particular difficulty manipulating mathematics concepts related to finance. The NADL-F-fr will be a useful tool in assessing and diagnosing Mathematical Learning Disabilities for adults who couldn’t be diagnosed during childhood. In addition, these results show the importance of working with ecological financial situations in rehabilitation.