Common Core State Standard 2.NBT.9
Number & Operations in Base Ten
Use place value understanding and properties of operations to add
9. Explain why addition and
subtraction strategies work, using place value and the properties of
*Explanations may be supported by drawings or objects.
Common Core State Standards: 2.NBT.9
Common Core State Standards:
Operations & Algebraic Thinking
Add and subtract within 20.
Fluently add and subtract within 20 using mental strategies. 2 By
end of Grade 2, know from memory all sums of two one-digit numbers.
Students complete fact families for given numbers.