Définition et Signification de "like Chinese arithmetic"

What is the origin of the idiom "like Chinese arithmetic" and when to use it?

The idiom "like Chinese arithmetic" has been used in the past to describe something that is excessively complex, confusing, or difficult to understand. The phrase might imply that Chinese arithmetic, or the methods used in Chinese mathematics, were perceived as intricate or puzzling by those unfamiliar with them.