This study explored cross-cultural teacher learning through a US-China lesson study. A framework combining professional noticing and cultural transposition was used to analyze lessons, exchanges, and interviews. Findings revealed shared goals, such as connecting mathematics to real life and emphasizing student thinking, with differences in approaches. US teachers focused on engaging students in contextual exploration, communication, and sense-making, while Chinese teachers guided students through a progressive exploration of mathematics using contextual problems. Observed differences also included beliefs about teaching, pedagogy, and class structure. By identifying similarities and differences, teachers reflected on their practices and challenged implicit cultural beliefs. A three-step framework was proposed for effective adaptation: attending to similarities and differences, deconstructing hierarchical dichotomies, and acting with intention. This research provides valuable insights for educators seeking to learn from and adapt international practices.