This article analyzes Malaysian and Japanese educators' reactions to a mathematics lesson observed by a subset of researchers. The main aims are to reveal the cultural scripts about mathematical learning that are held by, but often invisible to, members of a culture; and to address educators' conceptions of teaching mathematics across cultures. This study's emphasis is placed largely on understanding the logic behind the teaching scripts and the underlying epistemology of teacher pedagogical decisions. A qualitative analytical approach identifies the idea that focus on a single problem during a whole lesson enables opportunities for deeper learning (Japanese participants) or may be boring for students (Malaysian educators), and explores the value of, or problems associated with, extrinsic rewards. This research stands to make an important contribution, both through its novel method, and in its specific ideas about desirable qualities of mathematics lessons and how these might differ from the viewpoint of individual cultures.