Standard
- CCSS.Math.Content.1.OA
- Operations and Algebraic Thinking
- CCSS.Math.Content.1.OA.B
- Understand and apply properties of operations and the relationship between addition and subtraction.
- CCSS.Math.Content.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.