Number Talks is a popular K-12 mathematics routine utilized in classrooms across the United States. Number Talks allows teachers to elicit and respond to students' mathematical thinking through the development of an encouraging classroom community and provide opportunities for students to engage in critical thinking, collaboration, communication, and creativity. In this chapter, the authors report their “virtualization” of the Number Talks routine and the development of a teacher learning cycle that supports implementation of this practice. The virtualization of Number Talks is illustrated through the pedagogical transformation of one teacher, who begins the teacher learning cycle skeptical of the value of Number Talks and ends with an innovative Virtual Number Talks practice that benefited both students and teachers in her school. This teacher's implementation of Virtual Number Talks and engagement in the “4C” of 21st century learning demonstrate a transformation of pedagogy that uses technology to create rich online mathematics learning experiences.