Mathematical learning disabilities (MLD) are common developmental disorders in childhood. The term refers to a significant degree of impairment in a child’s mathematical skills. First, the problems are not a part of normal development, and remediation does not lead to improvements. Second, the problems are not originated in mental retardation or impairments in general intelligence. The child’s level of attainment is substantially below that expected for a child of the same mental age. Furthermore, the difficulties are part of a developmental trajectory. Third, problem onset must be early in the development of the child. In Flanders, most learning disabilities are not detected until primary school, when reading disabilities often become obvious. Likewise, many children with MLD in primary school do not encounter severe difficulties with preliminary mathematics learning in kindergarten, although in some cases inefficient counting and seriation was already present as a “marker” (Grégoire, 2005; Stock, Desoete, & Roeyers, 2007). Nevertheless, most children with MLD in Belgium are detected in grade 1 when they have to master addition and subtraction and, in some cases, even later (in grade 3), when they have to learn to retrieve quickly the times tables or to select and apply various problem-solving strategies in addition to the basic mathematical operations. Fourth, the impairments cannot be attributed to external factors that could provide sufficient evidence for academic failure. The fifth and last criterion states that the developmental disorders of academic skills are not directly due to uncorrected visual or hearing impairments (Desoete, 2008; Desoete, Roeyers, & De Clercq, 2004; Stock, Desoete, & Roeyers, 2006).