Illustrative MathematicsStandards for Mathematical Practice: Commentary and Elaborations for Grades K-5

Description: Mathematically proficient students understand and use stated assumptions, definitions, and previously established results in constructing arguments. They make conjectures and build a logical progression of statements to explore the truth of their conjectures. They are able to analyze situations by breaking them into cases and can recognize and use counterexamples. Mathematically proficient students understand and use stated assumptions, definitions, and previously established results in constructing arguments.