ABSTRACT
In this chapter, the author explores four curricular topics that are closely related to number sense: numeration, number magnitude, mental computation, and computational estimation. She also examines some other areas of learning that should be addressed when considering the role of instruction in developing number sense. A disposition toward making sense of numbers is discussed. An understanding of the many aspects and uses of numbers, particularly those related to cardinal and ordinal meanings and to the notion of place value, is fundamental to the acquisition of number sense. The foundations for the development of whole number sense were discussed in this chapter. The analysis of the foundations for rational number sense focuses on how fractions and decimal numbers are introduced, that is, how the texts attempt to link meaning to symbols, and then how numbers are compared and ordered.
