In this project, a university team of teacher education and mathematics professors conducted eight professional development sessions for General Educational Development (GED) teachers in the area of mathematics teaching. Topics included concretely modeling mathematics concepts in algebra, number sense, geometry, and differentiating instruction in classrooms of varied levels and ability. The team concluded that teacher confidence levels did increase. Finding differentiation in resources for teachers of adults was difficult. Providing hands-on mathematics manipulatives was valuable to the teacher participants.