Development of Learning Devices Based on Realistic Mathematics Education to Improve Students’ Critical Thinking Ability at MAN 1 Tanjung Pura

This study aims to: 1) develop the learning devices based on RME that meet the valid, practically, and effective criteria; 2) improvement of critical thinking ability of senior high school students by using learning devices based on RME developed. The type of this research is a development research. The development model used is Four-D Model which consists of 4 stages: define, design, develop, and disseminate. The results of the study show that: 1) the learning devices based on RME developed meet the valid criteria, both in the content validity and construct validity; 2) the learning devices based on RME developed meet the practical criteria, practically in terms of: a) validator assessment about ease of use of learning device, and b) implementation of learning devices. 3) the learning devices based on RME developed meet the effective criteria, effectiveness in terms of: a) students' learning mastery in a classical way; b) achievement of learning objectives; c) learning time; and d) students' positive responses; 3) An increased in students' critical thinking ability by using learning devices based on RME. Keywords: Development, Learning Devices, Realistic Mathematics Education, Critical Thinking