London, March 20 (IANS): As the world gears up for the wearable computer devices, back in the 17th century, one Chinese designer did create a functioning abacus 'smart ring’ that worked as a counting tool to help traders.

Developed by a famous mathematician Cheng Dawei of the Ming Dynasty, the ring features a 1.2 cm long, 0.7 cm wide abacus that sits on the finger.

The ring has seven rods with seven beads on each rod.

Despite its small size, the rings worked as a counting tool for traders to make quick calculations.

"It seems that the beads can only be moved by small tools such as pins. This was no problem for this abacus’s primary user - an ancient Chinese lady for she only needed to pick one from her many hairpins,” said a report on ChinaCulture.org.

Researchers in Norway made the discovery after studying the language of the tiny Pacific island of Mangareva, said the report.

Mangarevans had words for numerals one through to 10.

But for numbers 20 to 80, they used a binary system with separate one-word terms for 20, 40 and 80.

A typical elementary abacus has 10 parallel wires strung between two boards on a frame, with nine beads on each wire.

Each bead has a value of 10, a multiple or sub multiple of 10, the report added.