In this study I investigate Saldanha and Thompson's (1998) claim that conceptualizing a coordinate pair in the Cartesian coordinate system as a multiplicative object, a way to unite two quantities' values, supports students in conceptualizing graphs as emergent representations of how two quantities' values change together. I presented three university precalculus students with an animated task showing varying values of two quantities along the axes and asked each student to sketch a graph of how the two quantities changed together. In this paper I document the difficulty students encountered when they did not conceptualize a coordinate pair as a multiplicative object. I address why the convention of "over x and up y" inhibits students from constructing a coordinate pair as a multiplicative object and I provide recommendations for supporting students in constructing coordinate pairs as multiplicative objects. [For the complete proceedings, see ED583608.]