This chapter focuses on the powerful ideas of computational thinking as well as the habits of mind or practices that a young programmer develops. While the curriculum might use a particular programming environment, such as ScratchJr or KIBO, the powerful ideas and habits of mind, if they are indeed powerful, should be useful when coding with any language. The five powerful ideas from computer science such as algorithms, modularity, representation, control structures, and hardware/software, are all strongly linked to foundational concepts in early childhood education. These concepts span diverse disciplines such as literacy and math, arts and sciences, engineering, and foreign languages. There are two other kinds of powerful ideas that have more to do with processes, habits of mind, or practices than concepts: debugging and the design process. In the coding playground, a curriculum of powerful ideas provides thematic freedom to relate computer programming and computational thinking to other academic subjects.