Female teachers' math anxiety negatively affects girls' math achievement. This study shows that when female elementary school teachers experience math anxiety, it influences their students' beliefs about gender and math ability. Female teachers make up over 90% of elementary school teachers in the U.S., and their math anxiety is linked to girls' math achievement through their beliefs about who is good at math. The study found that by the end of the school year, girls who endorsed the stereotype that "boys are good at math and girls are good at reading" had significantly worse math achievement than girls who did not and than boys overall. This suggests that female teachers' math anxiety may reinforce gender stereotypes, which in turn affects girls' math performance. The study also found that the relationship between teacher anxiety and student achievement was mediated by girls' gender ability beliefs. These findings highlight the importance of addressing math anxiety in female teachers to improve girls' math achievement. The study also suggests that the minimal mathematics requirements for obtaining an elementary education degree in the U.S. may need to be reconsidered to ensure that future teachers have strong math skills and positive attitudes toward math.Female teachers' math anxiety negatively affects girls' math achievement. This study shows that when female elementary school teachers experience math anxiety, it influences their students' beliefs about gender and math ability. Female teachers make up over 90% of elementary school teachers in the U.S., and their math anxiety is linked to girls' math achievement through their beliefs about who is good at math. The study found that by the end of the school year, girls who endorsed the stereotype that "boys are good at math and girls are good at reading" had significantly worse math achievement than girls who did not and than boys overall. This suggests that female teachers' math anxiety may reinforce gender stereotypes, which in turn affects girls' math performance. The study also found that the relationship between teacher anxiety and student achievement was mediated by girls' gender ability beliefs. These findings highlight the importance of addressing math anxiety in female teachers to improve girls' math achievement. The study also suggests that the minimal mathematics requirements for obtaining an elementary education degree in the U.S. may need to be reconsidered to ensure that future teachers have strong math skills and positive attitudes toward math.