The widely adopted Common Core State Standards for Mathematics (CCSSM) are designed to deepen instruction of number sense and will demand that elementary school teachers have a strong understanding of number. These changes arrive at a time when it is still understood that teachers and the curriculum in the United States have not been fundamentally driven by number sense connections. Teachers, therefore, are faced with the need to reflect on their own instructional choices and to make changes in their classrooms--changes that encourage the development of number sense in their students in keeping with the demands of the CCSSM and that go beyond what they have formerly thought about number. For teachers of young students, the critical components of number sense are quantity, magnitude, numeration, different forms of a number, equality, and the language used to describe them. In this article, the authors discuss concepts that connect to the curriculum and process goals of the CCSSM and also tie directly to the Number and Operations Focal Points for prekindergartners (who should understand that number words refer to quantity) and for kindergartners (who should use numbers, including written numerals, to represent quantities). To help children understand the concrete concept that an abstract orthographic symbol represents, the authors suggest that teachers apply the same strategies they use for teaching background knowledge in reading. (Contains 6 figures.)