This book illuminates what studying mathematics means for both students and teachers and offers a broad range of insights into students' views and practices. In addition to the words of young people learning mathematics, the masculinity of mathematics is explored through historical material and cinematic representations. The author discusses the ways in which the alignment of mathematics with masculinity creates tensions for girls and women doing the subject. These tensions are sensitively explored through interviews with young men and women, to show how doing mathematics fits or conflicts with their gender identities. Finally, the book explores the implications for teachers, including ways to promote gender equity in mathematics education. Following an introduction, this book is divided into three parts. Part 1, Scene Setting, presents the first chapters of the book: (1) Engendering Mathematics; and (2) Introducing the Study. Part 2, Sex by Numbers, continues with chapters: (3) Being/Doing "Good at Maths"; (4) Proving Something to Others; (5) Proving Something to Themselves; and (6) Changing Directions. Finally, Part 3, Queering Gender and Maths, concludes the book with the remaining chapters: (7) Making Choices Social: Refusing Essences in the Classroom; (8) Supporting Gender Transgression: Being and Acting Different in Maths; and (9) Opening Up Mathematics: Living with Uncertainty.