North Carolina Standard Course of Study
NC.1.OA. Operations and Algebraic Thinking
Understand and apply the properties of operations.
NC.1.OA.4. Solve an unknown-addend problem, within 20, by using addition strategies and/or changing it to a subtraction problem.
Add and subtract within 20.
NC.1.OA.9. Demonstrate fluency with addition and subtraction within 10.
NC.1.OA.6. Add and subtract, within 20, using strategies such as:
NC.1.OA.6.a. Counting on
NC.1.OA.6.e. Using a number line
NC.1.NBT. Number and Operations in Base Ten
Extend and recognize patterns in the counting sequence.
NC.1.NBT.1. Count to 150, starting at any number less than 150.
Understand place value.
NC.1.NBT.3. Compare two two-digit numbers based on the value of the tens and ones digits, recording the results of comparisons with the symbols >, =, and <.
Use place value understanding and properties of operations.
NC.1.NBT.4. Using concrete models or drawings, strategies based on place value, properties of operations, and explaining the reasoning used, add, within 100, in the following situations:
NC.1.NBT.4.a. A two-digit number and a one-digit number
NC.1.NBT.6. Subtract multiples of 10 in the range 10-90 from multiples of 10 in the range 10-90, explaining the reasoning, using:
NC.1.NBT.6.b. Number lines