For many students, algebraic formulas are “abracadabra”: they lack symbol sense. Symbol sense includes identifying the structure of algebraic formulas, giving meaning to them, and reasoning with and about formulas. Besides basic skills, symbol sense is needed to solve algebraic problems and it is not known how to teach symbol sense systematically.
Click here for original story, Graphing by hand promote understanding of algebraic formulas
Source: Phys.org