In Sri Lanka, "badu" is a common Sinhala slang term that literally translates to "items" or "goods" but is often used colloquially to refer to girls, or more specifically, as a derogatory term for prostitutes

Only a handful of octogenarian salt traders in the remote villages of Bundala and Kirinda still remember the full lexicon. Anthropologist Nimal Wijesinghe, who documented the system in 1988, warns: “If we don’t record these numbers now, they will disappear like the traditional stilt fishing techniques. It’s not just math—it’s a memory of how coastal Sri Lankans outsmarted poverty and bandits with nothing but their tongues and knuckles.”

If you are traveling to Hambantota, knowing Badu numbers is not required, but it will earn you immense respect (and potentially a lower price). Here is a real-world scenario: