Thinking educators recognize that children of all ages need to have arithmetic related to their own experiences. Such a relation not only enriches living but lays an essential background for understanding arithmetic. It is only in this way that children may acquire the necessary understandings for arithmetical processes in a social background.12 "Experience units" are real and actual; "life situations" are built up and imaginary but made as nearly lifelike as possible, as, for example, a play store. .... The program for the first and second grades, as here developed, does not aim at drill results as such. It aims at meanings through experience.'3 A variety of illustrative experiences is included under each grade to indicate how children learn through living. These illustrations are actual situations where sensitive, alert teachers have promoted the child's growth through the use of number experiences as they arose in the classroom, in the home, or in the community.... Some are planned; others are incidental; all contribute to fuller understanding and more helpful instruction.'4