Common Core Alignment:.

2.NBT.2:

Number And Operations In Base Ten

Understand Place Value.

Count within 1000; skip-count by 5s, 10s, and 100s.

2.NBT.8:

Number And Operations In Base Ten

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

Mentally add 10 or 100 to a given number 100-900, and mentally subtract 10 or 100 from a given number 100-900.