1.NBT.5

=Number and Operations in Base Ten=
 * Use place value understanding and properties of operations to add and subtract.**

1.NBT.5 - Given a 2-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.

[|quick exit slip] [|Tool for finding 10 more/less] [|interactive 100 chart]