The main aim of this paper is to explain why certain parts of the Swedish New Math reform failed. The secondary aim is to nuance the idea about the decline of the New Math in Sweden . The analysis is focused on governance , but also ideological, economical and sociological aspects are considered. The main sources are syllabi, official reports and textbooks . Another type of source is a database of historical textbooks in mathematics. Even though the suggested explanation to great degree concerns the Swedish context, it has a more general relevance. Previous research on New Math in other countries is mainly focused on ideological and sociological aspects of the reforms. This paper also highlights the interplay between factors related to textbooks, governance and economics. It is relevant to consider these factors in other countries as well since textbook development was a part of New Math reforms in many countries.