It's usable, because although he doesn't understand what "addition, subtraction, multiplication, division" means, he has memorized the answers to basic arithmetic.
This is also why he often gets nosebleeds from overexertion; it's partly due to his young age and physical immaturity, but mainly because his computational method starts off massively.
"Is it Brother Yuan?"
The old man indeed had a different attitude towards Li Zhiyuan, adding a polite term after his address, unlike the straightforward 'fool' he called Tan Wenbin.
"Um-hmm," Li Zhiyuan responded, "hello."
"Yin Fuhai, seated at Fengdu Pier, may I ask which pier Brother Yuan sits at, or which Dragon King do you pay respects to?"
As he spoke, the old man also made a set of hand gestures commonly seen on the river docks.
Not every industry gives birth to jargon and hand gestures. These forms of identity confirmation are designed to resolve conflicts and prevent disputes.
