Understanding mathematical equivalence is foundational for developing early algebraic thinking. Despite its importance, many young students struggle with the concept and use incorrect strategies when solving equivalence problems. Immediate, computer-based feedback may help students learn correct strategies. However, designing effective feedback for math equivalence is challenging. In this work-in-progress paper, we discuss usability studies and child-centered design with young students. Our goal is to better understand how students make sense of different kinds of feedback, what kinds of formats they prefer, and what actions they take after receiving the feedback. By centering young students’ perspectives in the design process, we can avoid blind spots created by our adult researcher perspectives and increase the likelihood of student engagement and knowledge gains. We describe the extended iterative process required to help students develop a formal understanding of math equivalence by creating usable and effective computer-based feedback.