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

striking similarity between the original German-speaking participants and the Italian children.
Again, the vast majority of children (71 out of 97 Italian-speaking children) had a breakpoint
around the hypothesized change from one- to two-digit number representation at 10 (see
Figure 3). This is also reflected by the median of the individual breakpoints equaling 9.82 (M
= 21.19, SD = 45.95).
80
Distribution of individual breakpoints
60
N
40
20
0
95
Figure 3: Distribution of individually computed breakpoints
(rounded to the nearest integer) and arranged in clusters
around the multiples of 10.
Taken together, our results strengthen the assumption of two separate but linear
representations for singe-digit and two-digit numbers as both Austrian and Italian children’s
estimates on the 0 - 100 scale are accounted for best by a two-linear model with an assumed
break point at 10 (see Figure 4 for an illustration of regression models based on the mean
estimation of all children). This also implies that the representations of two-digit numbers
may be an integration of the two single digits constituting the number. As German and Italian
differ in the way two-digit numbers are verbalized (see above) we were interested whether the
performance differences observed for the 0 - 100 scale were specifically driven by the
inversion properties of the German number-word system, albeit an identical underlying
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