Common Core Alignment:.

1.OA.1:

Operations And Algebraic Thinking

Represent And Solve Problems Involving Addition And Subtraction.

Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.2

1.OA.3:

Operations And Algebraic Thinking

Understand And Apply Properties Of Operations And The Relationship Between Addition And Subtraction.

Apply properties of operations as strategies to add and subtract.3 Examples: If 8 + 3 = 11 is known, then 3 + 8 = 11 is also known. (Commutative property of addition.) To add 2 + 6 + 4, the second two numbers can be added to make a ten, so 2 + 6 + 4 = 2 + 10 = 12. (Associative property of addition.)

1.OA.4:

Operations And Algebraic Thinking

Understand And Apply Properties Of Operations And The Relationship Between Addition And Subtraction.

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