The purpose of this study was to evaluate the implementation and impact of the Pack program. The Pack was developed by the New York Hall of Science (NYSCI) and includes a digital game and set of curricular and professional development resources that aim to support computational thinking teaching and learning in middle school science and computer science classrooms. The evaluation of the Pack was funded with an Education Innovation and Research grant from the U.S. Department of Education and was carried out by the American Institutes for Research (AIR) during the 2022-23 school year in New York City middle schools. AIR examined the Pack intervention's classroom implementation by teachers and their Grade 6-8 students as well as outcomes related to students' computational thinking skills and their attitudes toward problem solving. Overall, the study yielded promising results about the feasibility and utility of implementing the Pack in middle school science and computer science classrooms. Based on teacher survey and interview responses, teachers reported that NYSCI's professional development was helpful to their teaching and reported that the Pack digital game and lessons were valuable for computational thinking teaching and learning. Using teacher survey and extant data, AIR found that teachers were able to implement the Pack program components with fidelity. To measure the relationship between students' use of the Pack and outcomes related to students' attitudes toward problem solving and computational thinking skills, AIR administered a pre- and posttest survey of student problem solving attitudes and a computational thinking knowledge assessment. AIR found that there were no significant associations between students' use of the Pack and their beliefs about their ability to apply their problem-solving skills to new situations or their beliefs about problem-solving ability as a fixed trait. Similarly, there were no significant associations between teachers' or students' reported use of the Pack and students' scores on a computational thinking assessment. There were also no significant associations between students' reported participation in computational thinking while using the Pack and their scores on a computational thinking assessment.