The first calculating device is the Abacus. The Abacus is an ancient counting device that was used for mathematical operations such as addition, subtraction, multiplication, and division. It consists of beads or stones that can slide up and down on rods or wires, which are set in a frame. The abacus is still in use today, especially in Asia and Africa, and is often used by merchants, traders, and clerks to perform quick calculations.