F. Hidayati, I.M. Arnawa, S. Bahri
Critical thinking skills are complex thinking abilities, so they can determine what students must believe and do. An attempt to improve the critical thinking skill is by applying the constructivist approach to the learning tools. The learning device was tested on students' class XI of SMA N 2 Lubuk Basung. This research is development research that implements Plomp design. There are three stages that should be done. The first stage is the initial investigation stage (preliminary research). Next is the development stage (development or prototyping stage). Last is the assessment stage. This research is only limited to one to one stage because it is in the COVID-19 period. Three eleventh graders of SMA N 2 Lubuk Basung become the subject of this research. There are three instruments used in this study: validation sheets, student questionnaire responses, and interview sheets with teachers and students. If the learning tools satisfy content and construct validities, they are considered valid. The results of the validation of the RPP and LKPD experts were 0.95 and 0.96 with a valid category. The conclusion based on the research finding is that the constructivism-based mathematics learning tools for eleventh graders of SMA N 2 Lubuk Basung can be declared valid. © Published under licence by IOP Publishing Ltd.
Department of Mathematics Educations, Universitas Negeri Padang, Indonesia; Department of Mathematics, Universitas Andalas, Padang, Indonesia
