Numbers of solved exact arithmetic problems in Experiments 1, 2, and 3.

<p>Within experiments, numbers of solved problems are depicted as a function of subset and condition. In the approximation-first and the computation-first conditions, Subset 1 refers to commutative problems, and Subset 2 to noncommutative baseline problems. In the control condition, subsets 1 and 2 only contained noncommutative problems. Error bars reflect within-participants confidence intervals based on the MSe of the Condition X Subset Interaction [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0142551#pone.0142551.ref051" target="_blank">51</a>].