Grade 1
Domain Operations and Algebraic Thinking
Cluster Understand and apply properties of operations and the relationship between addition and subtraction.
Standard Understand subtraction as an unknown-addend problem. <span class='clarification'>For example, subtract $10 - 8$ by finding the number that makes 10 when added to 8.</span>

1.OA.B.4. Understand subtraction as an unknown-addend problem. For example, subtract $10 - 8$ by finding the number that makes 10 when added to 8.