The Common Core's Standards for Mathematical Practice encourage teachers to develop their students' ability to reason abstractly and quantitatively by helping students make sense of quantities and their relationships within problem situations. The seventh-grade content standards include objectives pertaining to developing linear equations in mathematical word problems. However, research has shown that generating linear equations to represent relationships in word problems is difficult for algebra students, especially when the word problems involve fractional relationships. The ideas shared in this article are derived from a problem-solving study with twelve students (four seventh graders, seven eighth graders, and one tenth grader) (Hackenberg and Lee 2015; Lee and Hackenberg 2014). During work on the Theo-Sam CD Stack Height problem, students were asked to generate equations to represent the relationship between two quantities. The study focused on investigating snapshots of students' fractional and algebraic thinking through task-based interviews. As researchers probed students' algebraic reasoning, they found that when students were encouraged to draw a picture and connect it to numerical examples, they were able to generate correct linear equations based on the understanding of the relationship between two unknown quantities. This article shares pedagogical strategies and prompts for teachers to consider when helping students develop linear equations based on quantitative reasoning.