Common Core Alignment:.

2.NBT.9:

Number And Operations In Base Ten

Use Place Value Understanding And Properties Of Operations To Add And Subtract.

Explain why addition and subtraction strategies work, using place value and the properties of operations.3

3.NBT.2:

Number And Operations In Base Ten

Use Place Value Understanding And Properties Of Operations To Perform Multi-Digit Arithmetic

Fluently add and subtract within 1000 using strategies and algorithms based on place value, properties of operations, and-or the relationship between addition and subtraction.