Visuospatial working memory and mathematical ability at different ages throughout primary school

• Visuospatial working memory (VWM) can be measured with on the fly item calibration.
• In VWM span tasks, forward = storage and backward = central executive don't hold.
• Item length predicts item difficulty best, but other variables matter too.
• VWM is strongly related to addition and subtraction, especially at a young age.
• VWM is less strongly related to multiplication and division, and without age trend.

In this study, three aims were addressed: (1) validating a visuospatial working memory task in Math Garden, an adaptive online tool in which item difficulty and person ability are determined on the fly, (2) investigating the contribution of different item characteristics to the difficulty of the visuospatial working memory items, and (3) investigating relations between visuospatial working memory and various math domains at different ages.The method was validated by showing that item ratings were stable and grade differences in ability were significant. Regression analyses on the item level showed that not only sequence length, but also other characteristics, such as type of task (forward or backward), explained variance in item difficulty. Finally, regression analyses on the child level showed that visuospatial working memory and mathematics were significantly related: especially for addition and subtraction in the lower grades. For multiplication and division this relationship was weaker and without age trend.