Font Size: 

This study aims to produce mobile learning learning media with Think Pair Share model to improve the mathematical communication ability of junior high school students in Segiempat material that is feasible to be used (valid), practical and effective. The type of this research is Development Research with ADDIE development model that is analysis, planning, development, implementation, and evaluation. From result of research can be concluded that (1) result of media expert validation equal to 80,5%, material expert 82,9% with eligible criterion and design learning expert equal to 89%. (2) result of practicality test based on student response obtained by 80,9% with practical criterion. (3) effectiveness seen from result of average of control class postes 70,69 and experiment class equal to 80,75, result of observation ability of mathematical communication of student which have increased by 41%. And the result of t test show t_hitung> t_tabel that is 3,641> 1,669 then H0 is rejected and H1 accepted, so it can be concluded that Mobile Learning with Think Pair Share model on quadrilateral material is effective to improve students' mathematical communication ability on rectangular material. Keywords: development, mobile learning, think pair share, mathematical communication skills.