K.NBT.1  Compose and decompose numbers from 11 to 19 into ten ones and
some further ones, e.g., by using objects or drawings, and record each
composition or decomposition by a drawing or equation
(e.g., 18 = 10 +8); understand that these numbers are composed of
ten ones and one,two, three, four, five, six, seven, eight, or nine ones