The perpose of this research is to know the increasing of the everage achievement of students by using line bilangan media matematika. And without using line bilangan media matematika, optimizing/developing a learning medium which is suitable with a learning material is useful for gaining good evalution. This research is categorized into classroom action research (CAR). The subjects of the research consist of 24 students.based on third grade students” learning result of the elementary school about simple friction lesson has shown an improvemen after the teacher applied line bilangan media matematika. This has shown that the mean of the third student in which they mean used to be calculated as 50,41 now have been improved into 76,25