Set Circle is a set of set operation teaching aids with colored disks as the core. Each piece is double-sided and erasable, with a soft magnetic backing that can be directly attached to a whiteboard or operating pad. The teacher uses red, blue, and green circles to represent different sets, and visually demonstrates union, intersection, difference, and Venn diagrams through actions such as overlap, separation, and complement. Equipped with transparent rings and scale pads, it can quantify the number of elements and support gradient teaching from kindergarten classification games to elementary school probability statistics. Students can swing and circle around with their hands, and abstract set relationships are immediately visible.