“…The ability to understand mathematical concepts as described in NCTM (2000) includes (1) defining concepts, (2) identify examples and not examples, (3) presents concepts in the form of diagrams, symbols, and models, (4) transform one form of representation to another, (5) get to know a variety of meanings and interpretations of concepts, (6) identify the properties of concepts, and compare and differentiate concepts (Ningsih & Paradesa, 2018). This explains the importance of students understanding mathematical concepts as goals of mathematics learning.…”