The word gist is defined as "the main or essential part of a matter." The GIST strategy (Cunningham, 1982) helps students read expository text and get the main idea. Students must then convey the gist of what they read in 20 words. The strategy is can be used with narrative text if students are asked to summariz after each chapter.
Websites on GIST:
GIST: A Summarizing Strategy for Use in Any Content Area
Video: Get the GIST
GIST Lesson Plan for Math Class - PDF
GIST: Establishing Comprehension