North Dakota Academic Content Standards
ND.1.OA. Operations and Algebraic Thinking
Understand and apply properties of operations and the relationship between addition and subtraction.
1.OA.4. Demonstrate understanding of subtraction as an unknown-addend problem.
Add and subtract within 20.
1.OA.6. Use strategies to add and subtract within 20. Fluently add and subtract within 10.
ND.1.NBT. Number and Operations in Base Ten
Extend the counting sequence.
1.NBT.1. Count forward and backward within 120, starting at any given number. Read and write numerals within 120. Represent a number of objects up to 120 with a written numeral.
Understand place value.
1.NBT.3. Compare two two-digit numbers based on meanings of the tens and ones digits, recording the results of comparisons with the symbols >, =, and <.
Use place value understanding and properties of operations to add and subtract.
1.NBT.4. Demonstrate understanding of place value when adding two-digit numbers within 100. Use concrete models or drawing strategies based on place value, properties of operations, and/or the relationship between addition and subtraction to add and subtract within 100. Relate the strategy to a written method and explain the reasoning used.
1.NBT.4.a. Add a two-digit number and a one-digit number.