Counting is an enormously complicated concept and thus takes a long time for children to master. Mien a child has learned to recite numbers (count by rote), he hastaken the first of many steps. We have already talked about the ways in which young children develop concepts about the physical world by sorting and ordering. A numeral, such as 3, has two meanings. On the one hand, it refers to a set of three items. This is called its cardinal meaning. On the other hand, it stands for the third item in a sequence. This is called its ordinal meaning