The Building Blocks to Colorado's Content Standards were developed to connect early childhood education to the K-12 content standards, to advocate for appropriate teaching strategies for preschool children, and to support awareness and understanding of early childhood foundational skills among parents and teachers. Five sets of building blocks are being developed, in the areas of science, social skills, the arts, reading and writing, and mathematics. This document is comprised of the reading and writing and the mathematics sets of building blocks. Both sets begin with an introduction summarizing research findings on the connection between quality early childhood programs and later academic, social, and emotional success. The reading and writing building blocks continue with a list of recommended teaching practices from the joint position statement of the International Reading Association and the National Association for the Education of Young Children. The mathematics building blocks continue with a discussion of mathematical literacy. Both sets of building blocks follow with a list of the relevant Colorado Content Standards for the K-12 system, followed by a more detailed description of each standard. This description is coupled with an Early Childhood Foundation for each standard--statements that reflect the types of experiences and interactions preschoolers need in order to develop the foundation for attaining the standards. Each individual standard is then broken down into three sections: (1) "building blocks for learning," describing skills appropriate for preschoolers, indicators of the early childhood curriculum that can be used as a guide in creating learning experiences and individualized plans for young children; (2) "steps for getting there," examples of interactions and experiences necessary for acquiring the building blocks, including descriptions of the adult's role as a facilitator of learning and suggestions for appropriate materials; and (3) examples of activities in which young children are engaged. The reading and writing building blocks section ends with a 13-item bibliography. The mathematics building blocks section ends with a 17-item bibliography and a list of 18 books for children. (KB)