This part is a reading on the content knowledge a K-12 computer science teacher needs, written for someone meeting much of it for the first time. Its scope comes from two documents. The Field 194 test framework lists the competencies and performance indicators that define what a computer science teacher is expected to know, and this summary covers every one of them. The framework in turn draws on New York's Computer Science and Digital Fluency (CS&DF) Learning Standards, which describe what K-12 students should learn, and which are worth reading alongside this part for a sense of how each idea appears at different grade levels. The summary is organized in five sections, one for each competency described in Part 2: the impacts of computing, computational thinking and programming, networks and system design, cybersecurity, and pedagogical content knowledge. Each competency opens with an overview of how its parts fit together, and each part begins by laying out the structure of its topic before working through it. Key terms are explained in the text where they first matter, then collected in a short list at the end of the part, so the lists also work as a reference when you come back later. The section on programming begins with a bridge from the Python you learned in our courses to the typed pseudocode used in much writing about algorithms.

Use this part to fill gaps. Skim what you already know, and slow down where an idea is new or where you can follow the words but could not explain them to a student. Headings carry the competency and indicator codes from Part 2, so you can move between the two. Footnotes point to the places in our courses where you first met an idea.