Proceedings of the Annual Meeting of the Cognitive Science Society

The primary numerical activities in kindergarten through third grade are aimed at developing an understanding of thestructure of base-ten numbers and learning to add and subtract with increasingly larger numbers. Many students in theU.S. continue to find this difficult. Thus, the most common instructional tools intended to support childrens learning ofthese ideas should be analyzed for their cognitive alignment and, if needed, redesigned for optimal learning. This studyreports the findings from a study examining the cognitive alignment of a standard hundred board for the more difficultsubtraction operation. Additionally, we investigate whether redesigning the hundred board such that addition goes up andsubtraction goes down is more optimal for subtraction.