300-year-old Chinese abacus ring was used during the Qing Dynasty to help traders.
Source.
[18th century Chinese teenager voice]
Haha and teachers said we wouldn’t have a calculator with us everywhere we go
300-year-old Chinese abacus ring was used during the Qing Dynasty to help traders.
Source.
[18th century Chinese teenager voice]
Haha and teachers said we wouldn’t have a calculator with us everywhere we go