The abacus was invented by Chinese mathematicians approximately 5,000 years ago. The abacus is occasionally hailed as the world's first computer, but the abacus is more accurately described as a counting device. After its invention, people all around the world began using the abacus to help with their calculations.
Rather than making calculations as modern computers do, the abacus merely keeps track of numbers so that a human can make the calculations more quickly. In some countries, the abacus is still in widespread use, and skilled operators can carry out simple calculations on one as quickly as other people can perform the same operations with a calculator.