  Symbolic equations are one of the many representations used in physics.
Understanding these representations is important for students because they are
how students access knowledge in physics. In this paper I build off of the work
by Redish and Kuo, which described the cultural differences between how math is
used in math class and physics class, and the work by Fredlund et al, which
described the importance of unpacking representations for physics student. I
will describe how differences in the goals of numeric and symbolic problem
solving lead to different set of affordances. In particular, the inability to
distinguish variables, knowns, and unknowns in symbolic problem solving is a
benefit when describing a generalized physical system. I also present evidence
that observed errors when trying to solve symbolic problems are due to students
acting on inappropriate cues associated with numeric problem solving.
