In Sri Lankan colloquial Sinhala, Badu (බඩු) simply means "goods" or "items." But in the context of Nuwara Eliya, "Badu numbers" refers to a traditional system of pricing, inventory codes, or vendor identification used by the region’s iconic and small retail shops. This article dives deep into what these numbers are, how they work, and why they are essential for anyone trading or shopping in Sri Lanka’s hill country.