Excerpt 2: Cluster 1.OA.B: Understand and apply properties of operations and the relationship between addition and subtraction. (Pages 9-14)

Description: Explanations and examples of how to implement the Operations & Algebraic Thinking standards in Grade 1. The goal in Grade 1 is for students to use Level 2 and Level 3 methods to extend addition and subtraction problem-solving beyond 10 (the Kindergarten expectation) to within 20. As you will see later, if students need more practice with counting-all strategies, it will be important to give them opportunities to solve problems best suited for counting all. Finally, Level 3 methods are important for understanding the use of place value strategies for addition and subtraction within 100.