The two studies examined in this paper compare the different mathematical opportunities provided in preschool classrooms in China, Japan, and the United States, with an emphasis on mathematical-themed books in classroom libraries. Study one presents the results of an online survey to examining the content of preschool classroom libraries in China (N = 134), Japan (N = 168), and the United States (N = 291). Study two presents data obtained from semi-structured interviews of teachers in China (N = 8), Japan (N = 8), and the United States (N = 8). The interviews examined teacher perceptions of how they teach mathematics, the importance of teaching mathematics, and the use of the classroom library as a venue for mathematics. Study one results indicated that teachers from all three countries encourage classroom library use; however, teachers from China reported more mathematics storybooks than their Japanese or United States counterparts. Study two results indicated that teachers from all three countries viewed mathematics as important and provided various mathematics learning opportunities to children throughout the school day. Chinese teachers reported providing the most mathematics learning opportunities using whole group instruction, mathematics centers, and free play. Japanese teachers reported few whole group forms of instruction other than circle time but reported providing opportunities for using mathematics during free play and other embedded activities. United States teachers indicated that mathematics learning occurred using whole group instruction and mathematics centers.