To help students’ adapt in a rapidly changing society, subject materials should incorporate learning components that feature knowledge, skills, thinking, and attitudes. Mathematics is commonly used in daily life, and it is vital for technological development and explaining economic phenomena. The term “mathematical literacy” is regarded as the main idea behind compulsory education in Taiwan. However, studies have often explored the objectives and implications of the mathematics curriculum rather than the design of subject materials for mathematical literacy. In this paper, based on a review of the literature, we propose that knowledge, application, disposition, and learning are the four components of mathematical literacy. Mathematical literacy-oriented subject materials can be designed based on a learning loop, which first translates real-life problems into mathematical problems and then uses the mathematical results to explain the context. This learning loop framework illustrates cognitive development of knowledge based on the genetic decomposition of APOS theory. The framework can be used to develop literacy-oriented mathematical subject materials with knowledge at the center, incorporating application, disposition, and learning and possessing implicit and explicit features. When designing teaching materials, some components can be excluded. The components of knowledge, application, disposition, and learning serve as the approach to teaching design rather than the sequence of cognitive development. The designers of subject materials should consider the development of both learners’ cognition and understanding of mathematical concepts. Moreover, the skills of knowledge application, mathematical perspective, and lifelong learning should be included in subject materials. Herein, several examples of possible directions for the design of subject materials are proposed, alongside suggestions for further investigations.