It's like a manual calculator. It helped them do math.
abacus
ancient China, the abacus
Credit is given to the ancient China but it was widely used in the ancient world
Probably in China but variations of it were used throughout the ancient world.
China invented the abacus .
An abacus, the Chinese use it not only to multiply but for many mathematical calculations.
China invented the Abacus.
They would use and abacus for math, and for writing, they would use paper and ink.
The abacus was originated in China in 3000 B.C.(:
the jeje fell off a tree when the abacus came to life in china
the abacus replaced the abaci
Abacus is an ancient multi-sensoring calculating tool