The purpose of the study was to identify possible causes of gender differences in mathematics achievement. Educators need to be aware that gender differences may exist and encourage all students in the study of mathematics. Annotations of 38 articles and a glossary are included. It was concluded that affective factors are responsible for differences when they do occur. These may include student, parent, and teacher attitudes, and experiences outside of the classroom. Eleven recommendations are provided including: (1) teachers should provide information about math-related careers and the amount of mathematics required to enter those careers; (2) teachers should provide activities which allow students to practice spatial skills; (3) research must continue to investigate further what can be done to close the gap in mathematics achievement; (4) the SAT should be examined to determine if it is a fair predictor of achievement for both males and females; and (5) parents should be made aware of the importance of mathematics for all students, not just males; and of how their own attitudes affect the attitudes of their children. (CW)