Abacus

An abacus is a simple, ancient calculating tool that has been used for centuries to perform arithmetic operations such as addition, subtraction, multiplication, and division. It typically consists of a rectangular wooden or plastic frame with rods or wires strung across, on which moveable beads are placed. Each rod represents a different place value (ones, tens, hundreds, etc.), and by sliding the beads back and forth, users can quickly and efficiently conduct calculations without the need for paper or modern electronic devices.

The abacus is thought to have originated thousands of years ago in ancient civilizations such as Mesopotamia, China, and Egypt. Over time, many different types of abaci were developed, including the Chinese suanpan and the Japanese soroban, each with its own layout and calculation methods. Despite the advent of modern calculators and computers, the abacus is still used in some parts of the world today, valued for its ability to foster mental arithmetic skills and provide a visual and tactile way to understand numerical concepts

It's also used by Eliot to make jokes about people who have trouble keeping up with technology.