Mathematics is the foundation course in many fields, but many students are afraid to of it. Determining a method by which to promote the student interest and enthusiasm is still a problem many researchers are trying to solve. However, a lot of studies have found that a combination of mathematics and everyday life things can improve student interest, and the math learning process, combined with appropriate teaching strategies, can enhance learning achievement. Therefore, in this study, addition and subtraction, which are the basis for mathematics and a beginning course, are chosen as the learning content, and Teams-Games-Tournament (TGT) learning strategy is used in the entire learning process. It is expected that students' motivation and interest would be aroused by using game-based learning and that learning performance would be improved as a result of competition in a peer tournament. All of the participants in this study were second grade primary students who used an interactive game-based learning system constructed as a virtual grocery store and combined with TGT learning strategy for the purpose of learning addition and subtraction. The results of the experiment indicated that the students who used the proposed learning system with the TGT learning strategy had higher performance during the learning process and that interactive game-based learning can effectively promote motivation and attitude toward a math course.