Opportunities matter when it comes to students' math attitudes and performance. Over two semesters, across treatment sections of college algebra students, we implemented a set of dynamic computer activities linking animations and graphs. Across all sections, we administered a fully online survey of students' attitudes toward math. Using mixed methods, we analyzed students' attitudes toward math and their performance on a course final exam. At the end of each semester, we found statistically significant differences between treatment and comparison students' perceived competence toward math. Furthermore, treatment students outperformed comparison students on the course final exam, with statistically significant differences on an item linked to the dynamic computer activities. When students have opportunities to interact with dynamic computer activities, it can impact their math attitudes and course performance. [For the complete proceedings, see ED606556.]