<p>Mathematics is often challenging for young learners due to its abstract nature, making the design of age-appropriate instructional tools essential. This study investigated the effectiveness of a situation-based interactive e-book in a flipped mathematics classroom for first-grade students in China. A quasi-experimental pre-test–post-test design was employed with 90 students randomly assigned to an experimental group, which used the interactive e-book, and a control group, which learned with instructional videos. Both groups received the same in-class instruction. The situation-based interactive e-book was developed in alignment with the national first-grade mathematics curriculum and integrated real-world scenarios with interactive features such as immediate feedback and virtual agents. The findings indicated that the situation-based interactive e-book significantly improved students’ learning achievement, motivation, and satisfaction compared to the control condition, while no significant difference was observed in learning attitudes. These results suggest that embedding mathematical concepts in familiar contexts through interactive digital tools can enhance elementary students’ engagement and performance in flipped classrooms. This study highlights the pedagogical value of situation-based e-books in early mathematics education, but further research is needed to establish their long-term impact and potential application in more advanced mathematical domains.</p>