Progressions for the Common Core State Standards for MathematicsDraft K Progression on Counting & Cardinality and K-5 Progression on Operations & Algebraic Thinking

Description: One of a series of documents describing the progression of a topic across several grade levels, informed both by research on children's development and by the structure of mathematics. Grade 3 students can be encouraged to move as early as possible from equal grouping or array models that show all of the quantities to similar representations using diagrams that show relationships of numbers because diagrams are faster and less error-prone and support methods at Level 2 and Level 3. For example in the count-by for 7, students might use the following mental decompositions of 7 to compose up to and then go over the next decade.