“…The representation ability is highly recommended in mathematics learning (Garderen, Scheuermann, Poch, & Murray, 2016). This ability is one of the priorities that must be developed in learning mathematics to build an understanding of concepts and mathematical proficiency that cannot be separated in mathematics learning (Oktaviyanthi & Supriani, 2017;Syafri, 2017) The mathematical representation ability is still considered a problem because many learners who have difficulties in visualizing (Fatmaryanti & Sarwanto, 2015;Garderen et al, 2016;Krawec, 2014) Lack of student representation development (Hutagol, 2013) students cannot represent the mathematical problems into mathematical expressions or images so that learners cannot solve the problem (Yusnita, Masykur, & Suherman, 2016) Nowadays, there are many learning models that can be used for maximizing the learning, some of them are Project Based Learning (PBL) and Guided Discovery Learning (GDL) models. The PBL model is a model that requires the students to be active throughout the process and teachers lead the process, provide feedback to the students and assess performance.…”