This report describes the alignment of the Common Core State Standards to the math curriculum at DC Bilingual Elementary Charter School in Washington, D.C., which educates all students in English and Spanish. The alignment of the curriculum has been a multiyear, iterative process. School administrators, as well as the school's instructional coaches, say that their laser-like focus on adopting, adapting, and adjusting a rigorous, standards-aligned curriculum has been key to the school's success. They note that their work developing the math curriculum, particularly their repeated deep-dives into the standards, has been vital to growing their capacity to support students in meeting the higher expectations. The curriculum development work at DC Bilingual is distinguished by several core practices: (1) leveraging pedagogical expertise and distributing leadership; (2) backward-mapping from the standards; (3) articulating changes in instructional practice necessary to deliver the curriculum, and building teachers' capacity to enact and refine these changes; and (4) regularly testing, observing, and revising curriculum. Two sidebars describe curriculum refinement in action and present questions for reflection. [For the main report, "Ambitious Leadership: How Principals Lead Schools to College and Career Readiness," see ED584804.]