Major Work & Progressions
Two interesting ways to "slice" the Common Core Content Standards are: Horizontally, looking at the focus in each grade level, and Vertically, looking at how subjects flow from grade to grade.
Horizontal Slice: Major Work
Major work at each grade level called for in the Common Core
Vertical Slice: Progressions
The Common Core State Standards in mathematics were built on progressions: narrative documents describing the progression of a topic across a number of grade levels, informed both by research on children's cognitive development and by the logical structure of mathematics. These documents were spliced together and then sliced into grade level standards. From that point on the work focused on refining and revising the grade level standards.
For the latest versions of the progressions, see the University of Arizona site.
For a detailed list of major, additional and supporting clusters by grade, please go to one of these pages:
Content Emphasis by Cluster: