Individuals who experience math anxiety are often characterized as math avoidant, with highly math-anxious students opting into fewer STEM courses and careers than their less-anxious peers. However, most of the existing literature focuses on global avoidance behaviors where math can be completely avoided; as a result, little is known about how math-avoidant tendencies impact decision-making in situations where it is impossible to completely avoid math, such as when math-anxious students are enrolled in a math course. In an effort to fill this gap in the literature, I conducted a series of experiments that investigated the relation between math anxiety and math avoidance in contexts where math engagement is required. Using expectancy-value-cost models of achievement motivation as a foundation, I developed a theory of math-specific effort avoidance which posits that math avoidance behaviors emerge for math-anxious individuals when they perceive the costs of effortful math engagement to outweigh its benefits. In Study 1, I tested my theory by evaluating the choice behavior of math-anxious individuals using a novel effort-based decision-making task. I found evidence in support of the effort-avoidance theory, as math-anxious individuals exhibited a tendency to select easier, low-reward options over harder, high-reward options when choosing math problems to solve. In Study 2, I explored the real-world consequences of math-specific effort avoidance by investigating whether math anxiety relates to students’ use of effortful study strategies when preparing for a mathematics exam. I found that math anxiety was associated with the avoidance of effortful problem-solving during exam preparation, and that this effort avoidance behavior partially mediated the association between math anxiety and exam performance. Finally, in Study 3 I investigated the utility of effortful math engagement for increasing the math performance of math-anxious individuals. The results from this study suggest that the utility of effortful problem-solving during exam preparation depends on practice problem accuracy, and that intervening on accuracy is important for improving the math performance of math-anxious students. Together, the findings from the current dissertation provide support for the theory of math-specific effort avoidance and highlight considerations for improving the math performance of math-anxious individuals.