This chapter describes a case study of leveraging mobile phones in mathematical education by enabling students to pose, solve, present, evaluate, discuss, and refine math questions using the Stanford Mobile Inquiry-Based Learning Environment (SMILE). SMILE is an inquiry-based mobile learning framework designed to increase student engagement, interaction, reflection, peer evaluation, competition, and collaboration while making learning outcome tracking more transparent and immediate in various learning scenarios. SMILE was found to engage students in heterogeneous/mixed-ability classes and promote both team collaboration and competition in learning math. The students in Argentina and Indonesia experienced a total of 1 week of the mobile inquiry-based math class using SMILE. The chapter introduces seven phases of SMILE that are applicable to math classroom environments and it also outlines the SMILE math model, its process, and initial findings. SMILE has great potential to cause a substantial pedagogical paradigm shift in math education, especially in the developing world.