North Carolina Standard Course of Study
NC.2.OA. Operations and Algebraic Thinking
Represent and solve problems.
NC.2.OA.1. Represent and solve addition and subtraction word problems, within 100, with unknowns in all positions, by using representations and equations with a symbol for the unknown number to represent the problem, when solving:
NC.2.OA.1.a. One-Step problems:
NC.2.OA.1.a.1. Add to/Take from-Start Unknown
NC.2.OA.1.a.2. Compare-Bigger Unknown
NC.2.OA.1.a.3. Compare-Smaller Unknown
NC.2.OA.1.b. Two-Step problems involving single digits:
NC.2.OA.1.b.1. Add to/Take from- Change Unknown
NC.2.OA.1.b.2. Add to/Take From- Result Unknown
Add and subtract within 20.
NC.2.OA.2. Demonstrate fluency with addition and subtraction, within 20, using mental strategies.
NC.2.NBT. Number and Operations in Base Ten
Use place value understanding and properties of operations.
NC.2.NBT.5. Demonstrate fluency with addition and subtraction, within 100, by:
NC.2.NBT.5.a. Flexibly using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.
NC.2.NBT.5.b. Comparing addition and subtraction strategies, and explaining why they work.
NC.2.NBT.5.c. Selecting an appropriate strategy in order to efficiently compute sums and differences.
NC.2.NBT.6. Add up to three two-digit numbers using strategies based on place value and properties of operations.
NC.2.NBT.7. Add and subtract, within 1,000, relating the strategy to a written method, using:
NC.2.NBT.7.b. Strategies based on place value