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

ABSTRACT
Over the last years, evidence accumulated that the magnitude of two-digit numbers is
not only represented as one holistic entity, but also decomposed for tens and units. Recently,
Zhang and Wang (2005) suggested such separate processing may be due to the presence of
external representations of numbers while holistic processing became more likely when one
of the to be compared numbers was already internalized. The latter conclusion essentially
rested on unit-based null effects. However, Nuerk and Willmes (2005) argued that
unfavourable stimulus selection may provoke such null effects and misleading conclusions
consequently. Therefore, we tested the conclusion of Zhang and Wang for internal standards
with a modified stimulus set. We observed reliable unit-based effects in all conditions
contradicting the holistic model. Thus, decomposed representations of tens and units can also
be demonstrated for internal standards. We conclude that decomposed magnitude processing
of multi-digit numbers does not rely on external representations. Rather, even when two-digit
numbers are internalized, the magnitudes of tens and units seem to be (also) represented
separately.
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