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

estimation was particularly poorer in German- as compared to Italian-speaking children.
However, no such language difference was present for items with a small interdigit distance
(e.g., “five and thirty” 53 instead of the correct 35), where incorrect processing of tens and
units resulted in a much less deviation error. Finally, the current data for Italian-speaking
children corroborated the assumption of first-graders’ initially having two separate and linear
representations for single and two-digit numbers (Moeller et al., 2009a) rather than one
overall logarithmic representation (e.g., Opfer & Siegler, 2007). Actually, the current results
for Italian-speaking children were identical to those observed for their German-speaking
counterparts as reported by Moeller and colleagues (2009a). In the remainder of this article
the implications of these results will be discussed in turn.
Language differences in estimation accuracy
On a general level we observed the number line estimates of Italian-speaking children
to be more accurate than the estimates of the German-speaking children on the 0-to-100 scale.
Interestingly, this difference did not seem to be driven by differences in age or IQ-test scores
since the German-speaking children who performed poorer on the number line task were on
average older and scored higher on the CFT-1 than the children of the Italian sample who
nevertheless performed better on the number line task 3 . Incorporating the T-values of the
CFT-1 as a covariate in all analyses did not change this overall result pattern. Moreover, as
the first grade curriculum for mathematics is more or less identical in Italy and Austria (both
comprising the mastery of numbers up to 20 and their cardinal and ordinal relations as well as
first arithmetic procedures within this range, see above) it is unlikely that differences in
mathematics education account for the observed performance differences favouring the
Italian-speaking children. Thus, age, intelligence-test scores or schooling differences do not
3 Please note that this difference remained even when taking the age group instead of grade as the reference
suggesting that it was not driven by differences in the age of the participants.
106