Preservice elementary teachers' attitudes towards mathematics are often negatively influenced by their K-12 education. Accordingly, teacher educators must allow preservice elementary teachers to experience mathematical instruction differently to change their attitudes toward mathematics and their conceptions about what it means to teach and learn mathematics. This qualitative case study describes preservice elementary teachers' experience in a mathematics methods course designing a task for guided inquiry instruction. The study reports on how participants describe the experience, the factors they say contributed to their success or failure with the experience, and the tensions that arise when preservice elementary teachers are asked to design a task for a learning approach they are unfamiliar with. The findings have implications for teacher education programs and professional development to support prospective and in-service mathematics teachers with student-centered instruction and recommendations for teacher educators who want to embed guided inquiry into their instruction. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]