North Dakota Academic Content Standards
ND.2.OA. Operations and Algebraic Thinking
Add and subtract within 20.
2.OA.2. Use mental strategies to fluently add and subtract within 20.
ND.2.NBT. Number and Operations in Base Ten
Use place value understanding and properties of operations to add and subtract.
2.NBT.5. Use strategies based on place value, properties of operations, and/or the relationship between addition and subtraction to fluently add and subtract within 100.
2.NBT.7. Demonstrate understanding of place value within 1000 when adding and subtracting three-digit numbers. Use concrete models or drawings and strategies based on place value, properties of operation, and/or the relationship between addition and subtraction to add and subtract within 1000. Use a written method to explain the strategy.