* Early mathematical skills*, which are learnt before comprehensive school in most countries,

*(Jordan, Glutting, & Ramineni, 2010; Kurdek & Sinclair, 2001; Lachance & Mazzocco, 2006). Studies using distinct mathematical subskills to predict later composite scores in mathematics provide more elaborate information. More precisely, counting skills (Aubrey et al., 2006; Krajewski & Schneider, 2009), basic arithmetic skills (Aunola et al., 2004), counting, number knowledge, nonverbal calculation, story problems and number combinations (Jordan, Kaplan, Locuniak, & Ramineni, 2007), calculation, number line and magnitude comparison (LeFevre et al., 2010), number reading (Passolunghi, Vercelloni, & Schadee, 2007) and mathematical-logical principles (Aunio & Niemivirta, 2010; Desoete, Stock, Schepens, Baeyens, & Roeyers, 2009; Stock, Desoete, & Roeyers, 2009) have been found to be good predictors of later mathematics performance. In other words, if a child has low early mathematical performance before school, she or he will most likely have problems learning mathematics in school (Jordan, Kaplan, Oláh, & Locuniak, 2006). In a worst case scenario, the child’s weak early numeracy skills develop into mathematical learning difficulties later on.*

**strongly predict later mathematical skills***, which make mathematics learning at school very difficult and diminish the possibilities for later occupational education (Mazzocco, 2007; World Health Organization, 1992).*

**Children with mathematical learning difficulties have significant problems in basic arithmetic skills**##### References

- Aubrey, C., Dahl, S., & Godfrey, R. (2006). Early mathematics development and later achievement: Further evidence.
*Mathematics Education Research Journal, 18*(1), 27–46. - Aunio, P. & Niemivirta, M. (2010). Predicting children’s mathematical performance in grade one by early numeracy.
*Learning and Individual Differences, 20*(5), 427–435. - Aunola, K., Leskinen, E., Lerkkanen, M. K., & Nurmi, J. E. (2004). Developmental dynamics of math performance from preschool to grade 2.
*Journal of Educational Psychology, 96*(4), 699–713. - Desoete, A., Stock, P., Schepens, A., Baeyens, D., & Roeyers, H. (2009). Classification, seriation, and counting in grades 1, 2, and 3 as two-year longitudinal predictors for low achieving in numerical facility and arithmetical achievement. J
*ournal of Psychoeducational Assessment, 27*(3), 252–264. doi:10.1177/0734282908330588 - Jordan, N. C., Glutting, J., & Ramineni, C. (2010). The importance of number sense to mathematics achievement in first and third grades.
*Learning and Individual Differences, 20*, 82–88. - Jordan, N. C., Kaplan, D., Locuniak, M. N., & Ramineni. C. (2007). Predicting first-grade math achievement from developmental number sense trajectories.
*Learning Disabilities Research & Practice, 22*(1), 36–46. - Jordan, N. C., Kaplan, D., Oláh, L., & Locuniak, M. N. (2006). Number sense growth in kindergarten: A longitudinal investigation of children at risk for mathematics difficulties.
*Child Development, 77*(1), 153–175. - Kurdek, L. A., & Sinclair, R. J. (2001). Predicting reading and mathematics achievement in fourth-grade children from kindergarten readiness scores.
*Journal of Educational Psychology, 93*(3), 451–455. - Lachance, J. A. & Mazzocco, M. M. M. (2006). A longitudinal analysis of sex differences in math and spatial skills in primary school age children.
*Learning and Individual Differences, 16*, 195–216. - LeFevre, J. A., Fast, L., Skwarchuk, S. L., Smith-Chant, B. L., Bisanz, J., Kamawar, J., & Penner-Wilger, M. (2010). Pathways to mathematics: Longitudinal predictors of performance.
*Child Development, 81*(6), 1753–1767. - Mazzocco, M. M. M. (2007). Defining and differentiating mathematical learning disabilities and difficulties. In D. B. Berch & M. M. M. Mazzocco (Eds.),
*Why is math so hard for some children? The nature and origins of mathematical learning difficulties and disabilities*(pp. 29–47). Baltimore, MD: Paul Brookes Publishing. - Passolunghi, M. C., Vercelloni, B., & Schadee, H. (2007). The precursors of mathematics learning: Working memory, phonological ability and numerical competence.
*Cognitive Development 22*, 165–184. - Stock, P., Desoete, A., & Roeyers, H. (2009). Predicting arithmetic abilities: The role of preparatory arithmetic markers and intelligence.
*Journal of Psychoeducational Assessment, 27*(3), 237–251. doi:10.1177/0734282908330587 - World Health Organization. (1992).
*The ICD-10 classification of mental and behavioural disorders: Clinical descriptions and diagnostic guidelines*. Geneva: World Health Organization.