1.NR.2.3
Recognize the inverse relationship between subtraction and addition within 20 and use this inverse relationship to solve authentic problems.
Example Problems
Solve the equation:
Solve the equation:
Solve the equation:
Khan Academy ResourcesAdd within 20Subtract within 20Subtract within 20 visuallyAdd & subtract within 20Add within 20 visuallyAdd and subtract within 20 word problemsAdding up to four 2-digit numbersAddition and subtraction word problems: superheroesAdding within 20 using place value blocksAddition and subtraction word problems: gorillasAdding within 20 using ten frames

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