Using addition to solve large subtractions in the number domain up to 20.

This study examined 25 university students' use of addition to solve large single-digit subtractions by contrasting performance in the standard subtraction format (12-9=.) and in the addition format (9+.=12). In particular, we investigated the effect of the relative size of the subtrahend on performance in both formats. We found a significant interaction between format, the magnitude of the subtrahend (S) compared to the difference (D) (S>D vs. S

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http://dx.doi.org/10.1016/j.actpsy.2009.10.012	DOI Listing