The role of spatial dimensionality in arithmetic word problem solving

This study investigated whether spatial alignment between external visual representations and the described problem context facilitates children’s arithmetic word problem solving. Primary school students (n = 152; Grade 4 and 5; age range: 8.5 – 12.3) solved 72 compare problems varying (within subjects) in object orientation (vertical, horizontal, neutral), bar orientation (vertical, horizontal, no-bar), and consistency (consistent vs. inconsistent relational statements). We hypothesized that matching the bar diagram’s orientation to that of the object in the text (e.g., vertical bars for buildings) would enhance performance, particularly in inconsistent problems that place greater demands on mental model construction. This hypothesis was not supported: bar orientation did not interact with object orientation, regardless of consistency. However, an unexpected but robust interaction emerged between consistency and object orientation, with smaller consistency effects for vertically oriented problems. This suggests that vertical spatial relations are more intuitively processed than horizontal or non-spatial ones—possibly due to their deeper grounding in embodied experience. These findings prompt a reconsideration of the role of spatial alignment in instructional design and open new avenues for research on how spatial dimensions shape mental model construction in arithmetic reasoning and beyond.