Abstract: Recent mathematics education literature has supported the importance of mathematics problem solving for elementary prospective teachers and for K-8 students. The publication of the Common Core Standards for Mathematics, and the Mathematical Practices (Common Core Standards Initiative, 2010), reiterate the importance of mathematics justification. Through implementing and studying the impact of non-routine challenge problems with elementary prospective teachers, while mentoring K-8 students, mathematics teacher educators can learn more about how to monitor and improve prospective teachers’ problem solving experiences in math methods courses, and technology can make the exchange of problem solving solutions possible. “Studying classrooms where [instructors push students to submit clear, convincing arguments] gives a glimpse of what math for children may be like in future classrooms…” (Rathouz, 2009).