Arizona's College and Career Ready Standards
AZ.2.OA. Operations and Algebraic Thinking (OA)
2.OA.B. Add and subtract within 20.
2.OA.B.2. Fluently add and subtract within 20. By the end of Grade 2, know from memory all sums of two one-digit numbers.
AZ.2.NBT. Number and Operations in Base Ten (NBT)
2.NBT.B. Use place value understanding and properties of operations to add and subtract.
2.NBT.B.5. Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.
2.NBT.B.6. Add up to three two-digit numbers using strategies based on place value and properties of operations.
2.NBT.B.7. Demonstrate understanding of addition and subtraction within 1000, connecting objects or drawings to strategies based on place value (including multiples of 10), properties of operations, and/or the relationship between addition and subtraction. Relate the strategy to a written form.
2.NBT.B.9. Explain why addition and subtraction strategies work, using place value and the properties of operations. (Explanations may be supported by drawings or objects.)