This research is conducted to produce a product that can organize learning well and can ease problem solving in learning especially mathematics. The resulting product is the development of learning models and create an easy techniques as a solution to complete multiplication in Elementary School (SD). This is motivated by the low ability to solve various multiplication problem that occurred in the 4th grade in Elementary School (SD). This data was obtained based on observation and interviews conducted with teacher’s classroom at some public Elementary Schools in Purwakarta district. In one of the public Elementary Schools it was found that only 25% of students were able control multiplication. Based on the problems, the research method use is Research and Development (R&D) Borg and Gall. Product design that will be developed and applied that is model of learning model of mathematics education model (T2ME) and technique of SuBatSaGa multiplication. Our Product design developed has been approved by the experts. The experts in this research that is lecturer of mathematics. Keywords: multiplication, Trans Model Mathematics Education (T2ME), SuBatSaGa technique.

The basis of this research is to observe the importance of improving the mathematical communication skill of elementary school students. In this case, this research attempted to discover learning alternative that could improve mathematical communication skill of students by employing Two-Stay Two-Stray (TSTS) cooperative learning model. This research aimed to examine students’ mathematical communication skill and mathematics learning improvement by employing TSTS model. The employed method was a quasi-experiment of the non-equivalent pretest-posttest control group design. The participants for this study were the 5th-grade students of one of the public elementary schools in one of the districts in Purwakarta Regency. In this study, 26 students were employed as participants for each experimental and controlled group. This research discovered that: 1) students’ mathematical communication skill improvement that was taught using TSTS learning model was higher compared conventional model; 2) TSTS model was found influencing the improvement of students’ mathematical communication skill; 3) students’ mathematics learning activity and process was more active and improved with TSTS model.