This project examines how adults access the magnitude of fractions when comparing values presented at different scales. Comparing fractions in their base form (e.g., 1/2 vs. 1/4) is relatively direct, but comparing across scales (e.g., 1/2 vs. 2/8) may require additional processing even though the two fractions share the same magnitude.

Adults complete a fraction verification task in which fractions are presented sequentially in base form (1/2, 1/4, 1/8) or scaled by ×2 (2/4, 2/8, 2/16) or ×3 (3/6, 3/12, 3/24). We ask two questions: (1) does a mismatch in scale impose a processing cost, and (2) is that cost modulated by the numerical distance between the compared magnitudes? Response times and accuracy are analyzed with repeated-measures ANOVAs.