{
  "id": "indian-numeral-system",
  "domain": "indian-mathematics",
  "type": "Concept",
  "title": "Indian Numeral System",
  "slug": "indian-numeral-system",
  "url": "/mathematics/indian-mathematics/indian-numeral-system/",
  "summary": "Place-value decimal system with zero, developed in India c.5th-7th century CE. Transmitted to Islamic world (al-Khwarizmi c.825 CE) and Europe (Fibonacci 1202 CE). The most consequential mathematical contribution in history.",
  "added_to_codex": "2026-07-09",
  "last_verified": "2026-07-09",
  "sources": [
    {
      "tier": 1,
      "citation": "Brahmagupta (628 CE). Brahmasphutasiddhanta. Trans. Colebrooke 1817."
    },
    {
      "tier": 1,
      "citation": "Plofker, K. (2009). Mathematics in India. Princeton University Press."
    },
    {
      "tier": 2,
      "citation": "Ifrah, G. (2000). The Universal History of Numbers. Wiley."
    },
    {
      "tier": 3,
      "citation": "Kaplan, R. (1999). The Nothing That Is. Oxford University Press."
    }
  ],
  "entry_status": "live",
  "reading_levels_available": [
    "curious",
    "exploring",
    "deep_dive"
  ],
  "completeness": 1.0,
  "codex_version": "2.5"
}