Math Worksheet Using Groups Of Tens And Ones To Count Up To 3 Digit ... These quick checks are designed to go with Grade 2 Number and Operations in Base Ten Common Core Standards. The following standards are covered: 2.NBT.A.1 - Understand that the three digits of a three-digit number represent amounts of hundreds, tens, and ones; example: 706 equals 7 hundreds, 0 tens, and 6 ones.