Children's number processing is context dependent

The aim of this paper was to test the hypothesis of a context dependence of number processing in children. Fifth-graders were given two numbers presented successively on screen through a self-presentation procedure after being asked either to add or subtract or compare them. We considered the self-presentation time of the first number as reflecting the complexity of the encoding for a given planned processing. In line with Dehaene's triple-code model, self-presentation times were longer for additions and subtractions than for comparisons with two-digit numbers. Alternative interpretations of these results in terms of more cognitive effort or more mental preparation in the case of addition and subtraction than comparison are discussed and ruled out.