Just answering... or thinking? Contrasting pupils' solutions and classifications of missing-value word problems

Upper primary school children often routinely apply proportional methods to missing-value problems, also when this is inappropriate. We tested whether this tendency can be broken if children do not need to produce computational answers to word problems. 75 6th graders were asked to classify 9 word problems (3 proportional, 3 additive, and 3 constant) and to solve a parallel version of these problems. Half of the children (SC-condition) first did the solution and then the classification task, for the others (CS-condition) the order was opposite. On the word problem test, children often over-used proportional methods, but the CS-condition performed better than the SC-condition, suggesting a positive impact of the classification task. On the classification task, most pupils took into account the underlying mathematical models, but they did not always distinguish proportional from non-proportional problems. The SC-condition erformed worse than the CS-condition, suggesting that solving the word problems first negatively affects later classifications.