In terms of “effective,” 12 students mentioned that the DGBL with e-books enabled them to learn in a more effective and efficient way. For example, A23 said that “Presenting the learning content in the digital games on e-books makes mathematics knowledge easy to understand. Those games are helpful to me in learning mathematics.” A1, A19, and A23 indicated that “It is great to learn mathematics in this way. We can play mathematical games and make notes about what we do not understand. It is helpful to do that.” A2 and A22 mentioned, “After learning with the digital games on e-books, mathematics becomes easier and understandable for me. I can solve more difficult questions now.” A22 mentioned that “I prefer lessons with the cloud e-book, as it can help me quickly understand mathematics.” A7, A9, A12, and A15 indicated that “It is easy to learn and my mathematics knowledge has improved.” A17 and A19 further indicated that “The e-books are handy and convenient for learning.”