The earliest known form of the abacus (the Latin word for “sand tray” derived from the ancient Greek ἄβαξ) likely originated in ancient Mesopotamia (modern-day Iraq) circa 2300 BCE. The Babylonians used a system based on sand or clay tablets with grooves where pebbles could be placed to count and calculate. The abacus was also used in ancient Egypt and Greece, where it was made of marble or wood with grooves for sliding counters. Then the Romans developed a hand-held version of the abacus using pebbles or counters, and it was widely used for trade and commerce.

The Chinese abacus, or suanpan (算盤/算盘, literally “calculating tray”), was developed during the Han Dynasty circa 2nd century BCE. It typically had two decks, with two beads on the upper “heavenly” deck and five on the lower “earthly” deck, representing different place values. It became widely popular during the Tang and Song Dynasties for performing calculations like addition, subtraction, multiplication and division.

In the 16th century CE Japan adopted the Chinese abacus and modified it over time. The Japanese soroban (算盤, そろばん) simplified the design to have one bead on the upper deck and four on the lower deck. This streamlined design became more efficient and easier to use for calculations.

So, how do they work? Each rod typically represents one digit of a multi-digit number laid out using a positional numeral system such as base ten (though some cultures used different bases), e.g. Roman and East Asian abacuses have a top deck (containing one or two beads) representing fives and a bottom deck (containing four or five beads) representing ones. Regardless, when using an abacus, a bead only gets counted when it’s touching, either directly or indirectly, what’s called the “reckoning bar” or “beam” that connects all of the rods.

If you really want to know how to use one, there’s a whole video playlist of lessons by The HEC Project HERE.

Despite the advent of electronic calculators in the 20th century, abaci [Ed: Or abacuses if you prefer] are still used in some parts of the world, particularly in education and mental arithmetic training. Countries like China and Japan still teach children how to use the abacus to enhance memory, concentration and mental agility.

Skilled abacus users, known as soroban masters in Japan, can perform calculations faster than a modern electronic calculator. American theoretical physicist Richard Feynman, who was noted for facility in mathematical calculations, wrote about an encounter in Brazil with a Japanese abacus expert, who challenged him to speed contests between Feynman's pen and paper, and the abacus. The abacus was much faster for addition and somewhat faster for multiplication. Feynman was only faster at division.

But the craziest application of the abacus doesn’t use one at all! Children in many countries, especially Japan and China, are so practised with the abacus that they are able to visualise one in their minds and use that to perform complex calculations without a physical tool. Watch this short video from the People’s Daily in China showing pupils in China's Gansu province doing mathematical calculations at a tremendous speed … writing with their right hands, and using their left hands to operate their visualised abaci.

Story Idea: Nils Benson
_______________________________

References

wikipedia.org/wiki/Abacus
wikihow.com/Use-an-Abacus

Images

1. Close-up of an abacus. Photo credit: António Sanmarful
2. Chinese abacus. Photo credit: Mark Richards
3. Reconstructed Roman abacus. Photo credit: Mike Cowlishaw
4. Gregor Reisch: Madame Arithmatica, 1508
5. Bi-quinary coded decimal-like abacus representing 1,352,964,708
6. Man in shop with abacus
7. Video Playlist: Abacus by The HEV Project
8. American theoretical physicist Richard Feynman (1918–1988)
9. Video: Pupils can do math at a tremendous speed using their left hands and mentally visualised abacus, People's Daily, China 人民日报