Addition & Subtraction Concepts

What is addition? What is subtraction? Representing addition & subtraction with models and number sentences.

Reasoning Strategies for Addition

Using a strategy: count on, using ten, using doubles. Representing addition strategies with models and number sentences: count on, using ten, using doubles.

Reasoning Strategies for Subtraction

Using a strategy: counting, using ten, using known facts. Representing subtraction strategies with models and number sentences: counting, using ten, using known facts.

Reasoning Strategies for Mental Math, Estimation & Algorithms

Counting with tens, using front-end strategies, benchmarks & nice numbers, known facts, bounds, rounding. Matching models and thinking, matching models and symbols, meaning of symbols.

Using Properties & Generalizations

Addition: Commutative, Associative, Identity, & Inverse. Addition & Subtraction Generalizations. Equity Propertis: Reflexive, Symmetric, Transative, & Subtitution.