Every educator knows the sinking feeling of a lesson gone wrong. As teachers look around the room and realize that many of their students are just not getting it, they often feel like failures. However, the struggle students experience as they persevere through high-quality challenging tasks is not a sign of failure, but rather a key aspect of engaging and equitable mathematics instruction (National Council of Teachers of Mathematics [NCTM], 2014). This is especially true when challenging tasks provide multiple entry points that allow students of all ability levels to use their individual background knowledge to employ a range of strategies. Moreover, observing students struggling through challenging tasks provides teachers with opportunities to uncover their students' mathematical thinking (Baker et al., 2020)--including their misconceptions--and facilitates in their students a strong conceptual foundation upon which future learning can take place. This article provides a classroom example of how these results can be achieved as teachers engage their students in productive struggle, where challenging problems are viewed as "opportunities for delving more deeply into understanding the mathematical structure of problems and relationships among mathematics ideas, instead of simply seeking correct solutions" (NCTM, 2014, p. 48).