The unit of “Line symmetry figures” in the elementary mathematics course was designed for the game-based learning model. It included the “Awareness of line symmetry figure-related buildings in life” (a game of selecting the two completely equivalent figures from three), “Knowing axis of symmetry and counting axis of symmetry” (games of a rhombus being folded for up–down or left–right overlapping figures, and an isosceles triangle being folded for left–right overlapping figures), “Knowing point of symmetry, side of symmetry, and angle of symmetry” (a game of line symmetry figures), “Drawing line symmetry figures” (a game of drawing line symmetry figures with grids), and “Exercise” units. Figure 2 shows the learning scenarios of using e-books to play the mathematics games in the classroom.