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.
1.NBT.5:
Number And Operations In Base Ten
Use Place Value Understanding And Properties Of Operations To Add And Subtract.
Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.
K.CC.1:
Counting And Cardinality
Know Number Names And The Count Sequence.
Count to 100 by ones and by tens.
