When a child understands number relationships, he or she comprehends the meaning of numbers by developing multiple, flexible ways of representing them. The importance of developing number relationships in the early years has been highlighted because it helps children build a good foundation for developing a more sophisticated understanding of number and quantity; therefore, teachers of young children must provide rich experiences with number relationships, which allows students to develop flexibility in representing numbers. Three types of number relationships (i.e., subitizing, more-less, and parts-whole relationships) can be taught in early childhood classrooms. This article outlines these number relationships, follows with the classroom activities that Becky, a preschool teacher in a university-affiliated program, presented in her preschool classrooms, and discusses effective instructional approaches for teaching number relationships. (Contains 4 figures and 1 table.)