Arithmetic word-problem solving requires the construction of a mental representation of the
situation described by the text. Devidal, Fayol and Barrouillet (1997) showed that the number of
successful solutions is higher when the question is posed before rather than after the text.
According to these authors, the question at the beginning of the text activates the appropriate
resolution schema. This schema allows calculations during reading, as soon as the numerical data
required for these calculations are presented. The subsequent release of working memory
resources would explain the improvement in performance. In the present experiment, we used an
original paradigm that allows us to determine precisely when the calculations occur. The results
confirm the facilitative effect of the question at the beginning of the text and extend this resuit to
more complex problems than those studied by Devidal et al. (1997). However, we show that this
effect is observable whether the calculations are achieved during reading or not. These results are
discussed with regard to schema and mental model theories.
Key words : arithmetic word-problem solving, mental representation, schemas, mental models.