eng Science and Education Publishing American Journal of Educational Research 2327-6150 2020-01-18 8 1 58 65 10.12691/education-8-1-9 EDUCATION2020819 article Marizqa Khairunnia marizqakhairunnia123@gmail.com 1 H Hasratuddin 1 Dian Armanto 1 Mathematics Education, Postgraduate Programme, State University of Medan, Medan, Indonesia This study aims to analyze: 1) the validity, practicality, and effectiveness of the learning devices based on RME approach developed, 2) improvement of problem solving abilities using the developed learning devices, 3) students using the developed learning devices. This research is a research development (research and development), the product produced is the implementation of learning plans, student activity sheets, and student books. The development of learning devices based on RME approach was developed using Thiagarajan's 4-D development model with 4 steps: defining, designing, developing, and disseminating. From the results of trial I and trial II obtained: 1) the learning devices obtained meet the valid, practical and effective criteria. Practical criteria are reviewed from: a) Validator assessment and b) implementation of learning devices, while effective criteria, in terms of: a) classical learning outcomes, b) achievement of learning outcomes, c) learning, and d) positive student responses. 2) There is an increase in students 'problem solving abilities using developed learning devices, 3) there is an increase in students' ability to use developed learning devices. http://pubs.sciepub.com/education/8/1/9/education-8-1-9.pdf development learning devices realistic mathematics education problem solving ability mathematical disposition