Abstracts - Earli

Noel, 2001), assess five facets of the numerical development: (1) counting, (2) representation ofnumerosity, (3) computation, (4) knowledge of the numerical system, and (5) logical operations.The test was standardized in France and French-speaking Belgium. This research investigated theconstruct validity of the tasks included in the fifth facet, which is related to the Piagetian model ofnumber. Our results showed a very significant relationship between logical reasoning, assed by thePiagetian tasks, and arithmetical abilities at grades 1 and 2. These results emphasized thediagnostic usefulness of Piagetian tasks included in the TEDI-MATH.The role of logic thinking, counting and knowledge of the number row on arithmetic abilities inpreschoolersPieter Stock, Ghent University, BelgiumAnnemie Desoete, Ghent University, BelgiumHerbert Royers, Ghent University, BelgiumBesides the Piagetian logical operations, several other prenumerical arithmetic abilities seem to beimportant in the development of arithmetic. The importance of those abilities is however debatedheavily and the relation with important arithmetic domains like conceptual and proceduralknowledge still remains obscure. In this study, the relation between six prenumerical arithmeticabilities -knowledge of the number row, counting, seriation, classification, conservation andinclusion- and conceptual and procedural arithmetic knowledge was investigated. 242 preschoolerswere assessed with different subtests of the TEDI-MATH. The results show that scores onprocedural knowledge can be predicted in almost ninety percent of the children based on theachievement on the six prenumerical arithmetic abilities. For conceptual knowledge, onlyknowledge of the counting row, seriation and inclusion seem to be important. Longitudinal designsare needed in order to investigate causality and the sentence of the relationships between thedifferent factors.Gender differences in acquiring the base-10 system of multi-digit numbersHelga Krinzinger, University Hospital RWTH Aachen, GermanyLiane Kaufman, Innsbruck Medical University, AustriaHans-Christoph Nuerk, University of Salzburg, AustriaKlaus Willmes, University Hospital RWTH Aachen, GermanyGender differences regarding complex mathematical skills favouring males have been repeatedlyreported (e.g. PISA, 2003). A popular neurocognitive explanatory hypothesis is the so-called‘spatial cognition hypothesis’ (Casey et al., 1992) emphasizing a correlation between spatialcognition and complex computational skills. Considering the spatial orientation of the ‘mentalnumber line’ (Dehaene, 1992) and the fact that successful retrieval of numerosities requiresflawless orientation on the mental number line, gender differences should also emerge regardingbasic number processing. Upon collecting normative data for the German version of thecalculation test TEDI-MATH 875 children aged 4 to 8 were subjected to tasks tapping abstractcounting principles, counting skills, number comprehension, computational skills and approximatenumber comparison. Findings revealed that males outperformed females on the following subtests:transcoding (first and second grade), number comparison (second semester of first grade andsecond grade), base-10 system (second semester of second grade) and some aspects of exactcomputation (first and second grade). On the contrary, gender differences did not reachsignificance in kindergarten and third grade (the latter might be explained by ceiling effects).Overall, our results suggest that males might develop an earlier understanding of the base-10– 130 –