BOOK REVIEW:  FIVE LITTLE DUCKS, a traditional song illustrated by Sylvia Ion, is a repetitive story that also uses the math concept of subtraction.  The ducks are subtracted as, one by one, a child lifts a little duck from the water and carries it away.  We discover, near the end of the story, that the child is trundling them off to a huge glass bowl filled with water.  The child releases all five little ducks back into the pond and Mamma duck's objections cease as they form an ordered train and swim away.