Recent data on national numeracy testing related to understanding of the fraction concepts indicate that many Year 7 students struggle with these difficult concepts. But do teachers and prospective teachers may have the necessary content knowledge to assist their students? In this study, 159 pre-service teachers undertook a fractional knowledge test, which contained items from recent Year 7 national numeracy tests. It was found that many of the pre-service teachers struggled with most of the questions. The implications of this finding for pre-service teacher education are discussed.