In the SQR3 system (Survey, Question, Read, Recite, Review), the "survey" step involves getting an overview of the material before diving deeper. Among the strategies you listed, "scan for organization" would fall under the survey step. It involves looking over the headings, subheadings, and any other structural elements of the text to understand its layout and main ideas.
The other strategies you mentioned—take notes, summarize, and ask and answer questions—are part of different steps in the SQR3 system.