like Chinese arithmetic

said of something that is very complex or difficult for one understands or work with

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.

Trying to decipher the professor's equations felt like Chinese arithmetic.The symbols and formulas were so intricate and confusing.
Understanding the new tax regulations was like Chinese arithmetic for most people.The rules and calculations were incredibly complex.
Figuring out the software's coding requirements seemed like Chinese arithmetic to the inexperienced programmer.The logic and syntax were difficult to grasp.
Solving the advanced Sudoku puzzle was like Chinese arithmetic for me.The patterns and combinations required a level of logical thinking that I found challenging.
Navigating through the city's intricate subway system felt like Chinese arithmetic to the tourist.The numerous lines, interchanges, and maps were overwhelming.