Mathematical knowledge for teaching (MKT) is often thought of as a transformed, mutually-influencing mixture of content and pedagogy. However when individuals' MKT does not integrate content and pedagogy, one type of knowledge can supersede the other, sometimes unconsciously. We exemplify this with Emma, a prospective elementary teacher, whose views on students' learning needs overshadowed her content knowledge. Specifically, Emma answered mathematical questions incorrectly, despite being aware of the correct answers, because she inadvertently gave more weight to pedagogical than to mathematical concerns. Implications for research and teacher education are discussed.