sc Go Developmental dyscalculia

to t ere y an mat sing nde is a lea betwee en use ic lear lties; M descr often learning, or number sense (Butterworth, 2005), whereas the terms impairment of mathematical skills of developmental origin and explore the effects of using different diagnostic criteria on preva-lence and gender ratio in a UK population of 1004 children aged 7e10 years. discrepancy definition, in which maths performance scores were pancy ’ value) and 5). Second, others impairment using e range of cutoffs d in Fig. 1. These the 3rd percentile to 0.68 SD below the mean). Third, DD has also been defined using a two year achievement delay as a diagnostic criterion, that is, children were categorised as having DD if their mathematics performance was equal to or below the average level of children two years younge