This study analyzed the cognitive functioning underlying arithmetical difficulties and explored the predictors of arithmetic achievement in the last three grades of Spanish Primary Education. For this purpose, a group of 165 students was selected and divided into three groups of arithmetic competence: Mathematical Learning Disability group (MLD, n = 27), Low Achieving group (LA, n = 39), and Typical Achieving group (TA, n = 99). Students were assessed in domain-general abilities (working memory and PASS cognitive processes), and numerical competence (counting and number processing) during the last two months of the academic year. Performance of children from the MLD group was significantly poorer than that of the LA group in writing dictated Arabic numbers (d = –0.88), reading written verbal numbers (d = –0.84), transcoding written verbal numbers to Arabic numbers (–0.75) and comprehension of place value (d = –0.69), as well as in simultaneous (d = –0.62) and successive (d = –0.59) coding. In addition, a specific developmental sequence was observed in both groups, the implications of which are discussed. Hierarchical regression analysis revealed simultaneous coding (β = .47, t(155) = 6.18, p < .001) and number processing (β = .23, t(155) = 3.07, p < .01) as specific predictors of arithmetical performance.

This study identified the cognitive processes that underlie the individual differences in early mathematical performance in elementary school children. Taking into account the Baddeley framework multicomponent model, the inhibitory processes, working memory, phonological awareness, and naming speed are considered to be related to early math learning. To examine this relationship, we compared the performance of a total of 424 typically developing middle-class children, aged between 4 and 7 years in a battery of cognitive and early numeric tests: The Utrecht Early Numeracy Test, the Rapid Automatized Naming Test, Spanish version of the Stroop task, the Numeracy Interference Test, Digit Span test, and Phonological Knowledge Test. The mean age of the participants was 72.21 months (sd = 14.8), and 48.6% were male and 51.4% were female. The results demonstrated that children performing worst on central executive, phonological processing, and inhibitory processes showed lower results in early mathematical tasks measured by The Utrecht Early Numeracy Test. Results supported the notion that the executive system is an important predictor of children's mathematical performance.