The influence of the place-value structure of the Arabic number ...

The developmental influence of place-value knowledge
In discussing the influence of place-value understanding on the development of
numerical competencies in children two different lines of evidence pursued in the current
thesis shall first be evaluated and then integrated. On the one hand, the place-value knowledge
structure of the Arabic number system may influence the way basic numerical representations
are shaped (cf. Zuber et al., 2009). This aspect of early place-value knowledge was addressed
by Study 3. On the other hand, early place-value understanding may be an important predictor
of later arithmetical skills as investigated in Study 4. Such a predictive association has already
been observed for other basic numerical representations such as the representation of number
magnitude (cf. Holloway & Ansari, 2009). These two aspects of the developmental influence
of the place-value structure of the Arabic number system will be discussed in turn.
The influence of early place-value processing on the development of the mental number line
Only recently, Zuber and colleagues (2009) found that even a task as basic as
transcoding a number from spoken to written format is influenced by aspects relating to placevalue.
The authors found that in German-speaking children about half of all transcoding errors
committed were related to the inversion property inherent in German number words [e.g.,
writing down 72 instead of 27 when dictated “siebenundzwanzig” (literally: seven and
twenty)] and thereby possibly determined by confusion in place-value integration of the single
digits, i.e., difficulties in assigning each digit its corresponding power level as these are
inverted in German number words as compared to symbolic notation. Thus, this indicated an
influence of the place-value structure of the Arabic number system on other numerical
representations such as the verbal representation of number words and related task such as
transcoding. In this context, Moeller et al. (2009b) observed that place-value influences may
not be limited to the development of transcoding skills but also to building up the spatial
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