1st Grade 1.NBT.B.2.C Math Number Operations in Base Ten Printable Worksheet PDF. Common Core State Standard 1.NBT.B.2.C The numbers 10, 20, 30, 40, 50, 60, 70, 80, 90 refer to one, two, three, four, five, six, seven, eight, or nine tens (and 0 ones).
