One disadvantage for teachers at all levels of education is trying to keep up with changing technologies and learning how to use both hardware and software for educational purposes. Additionally, teachers must learn how to ensure that students are learning skills rather than simply learning how to efficiently use technology. For example, using a graphing calculator in a geometry class may make it easier for students to find angle measures without understanding properties of a triangle. Teachers can also find the amount of student communication via email overwhelming if they have increased numbers of students.