This study compared area lessons from Korean textbooks and US standards-based textbooks to understand differences and similarities among these textbooks, as well as how these textbooks address known learning challenges in area measurement. Several well-known challenges have been identified in previous studies, such as covering, array structure, and linking array structure to area formula. We were interested in knowing if textbooks addressed these issues in their treatments of area measurement, and in doing so provided students with opportunities to overcome or become familiar with known challenges. The results show that both countries textbooks demonstrated similar limitations, only few area and area related lessons are covered and three important learning challenges in area measurement are not covered well, which need to be informed to practicing teachers. [For the complete proceedings, see ED606531.]