Vintage Abacus

The abacus, also called a counting frame, is a calculating tool which has been used since ancient times. It was used in the ancient Near East, Europe, China, and Russia, centuries before the adoption of the Hindu-Arabic numeral system. The exact origin of the abacus is not known. It consists of rows of movable beads, or similar objects, strung on a rod. They represent digits. One of the two numbers is set up, and the beads are manipulated to perform an operation such as addition, or even a square or cubic root.In their earliest designs, the rows of beads could be loose on a flat surface or sliding in grooves. Later the beads were made to slide on rods and built into a frame, allowing faster manipulation. Our abacuses are Chinese and range from 40-100 years old, most recently used by market vendors. Many show signs of repair, which is highly desirable. The beads are quite dense and heavy and...