Students enrolled in introductory math courses, such as college algebra, deserve to do more than find answers and fix mistakes. We present one interactive digital activity, the Cannon Man "Techtivity," which we developed to provide opportunities for students to develop an understanding of function, beyond just applying a rule, such as the vertical line test. With an accompanying facilitation guide, we describe how we promote instructor moves to privilege student reasoning. We provide student data to support the effectiveness of this approach. We conclude with implications for weaving such opportunities into the fabric of college algebra.