We all have the experience of pinching bubbles, and this unconscious movement and psychological perception always makes people happy and relaxed. The design grafts this perception onto the keys of the calculator, and when you press it, it will evoke memories of your pinch bubble: "Oh, this is the feeling of pressing bubbles." The calculator button is made of silicone and filled with liquid. When the button is pressed, the number will slide in the water, adding an invisible interest to the calculator operation.