Comparing examples of two solution methods was shown to be preferable for specific
aspects of learning to solve linear equations. Students in one group learned to solve linear
equations such as 3(x+1)=15 using the Btraditional^ solution method: Bdistribute, combine
like terms, subtract constants and variables from both sides, and then divide both sides by the
coefficient^ (Rittle-Johnson & Star, 2009). In the other group, students were instructed also to
use an alternative solution method. They were taught to see such expressions as Bx+1^ as one
composite variable and, for example, to first divide both sides of the expression by 3 in the
presented sample equation. Comparing examples of two solution methods was found to
positively affect students’ conceptual knowledge of solving equations, which includes Bthe
ability to recognize and to explain key concepts in the domain^, and their procedural
flexibility, which refers to the Bflexible use of solution methods on the procedural knowledge
assessment^ (Rittle-Johnson & Star, 2009, p. 532)