Several research works have suggested that, in some marginalized and peripheral contexts, the low achievement of students in the field of mathematics is correlated with the negative representations associated with this field of knowledge, produced by cultural prejudices and stereotypes vehiculated by social institutions (as school) and families. Following this hypothesis, this paper presents the results of a study conducted in a multicultural context, the French West Indies public primary school system, using a psychometric tool (Mathematical School Readiness Test. N= 2710), combined with a sociological survey on mental representations of mathematics (N= 86). The results confirmed the pivotal role played by didactic issues and identify some teaching strategies aimed to facilitate the learning process associated with mental calculation.