{
  "vercy": "1.0-draft",
  "publication": {
    "status": "research-draft",
    "adjudicationStatus": "unreviewed",
    "publishableCanonical": false,
    "generatedAt": "2026-09-12T20:35:42Z",
    "providers": [
      "Claude"
    ],
    "breadth": "written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify",
    "pass": 2,
    "wave": 3,
    "engine": "claude",
    "enrichment": {
      "pass": 3,
      "engine": "claude",
      "producedAt": "2026-10-06T10:00:00Z",
      "ingestedAt": "2026-10-06T06:59:06+00:00",
      "fields": [
        "agent_conduct",
        "ethics",
        "owners"
      ]
    },
    "gate": {
      "passed": true,
      "version": "1.0",
      "at": "2026-10-06T19:52:01+00:00",
      "evidence": [
        "completeness 1.00",
        "sense: Wikidata description",
        "2 live sources",
        "review by codex: pass"
      ]
    }
  },
  "metaModel": {
    "id": "THING-Q66055",
    "registryId": "vr.tr.fraction",
    "name": "fraction",
    "version": "0.2.0-wave.3",
    "entryKind": "thing",
    "family": "Thing Registry",
    "domain": [
      "INF.MED"
    ],
    "status": "research-draft"
  },
  "canonicalUrl": "https://ver.cy/models/thing/q66055/",
  "model": {
    "registry_id": "vr.tr.fraction",
    "name": "fraction",
    "purpose": "Let an agent explain fractions and their arithmetic, distinguish fractions as notation from rational numbers as values, support learning and calculation, and route specialised uses to their entries.",
    "definition": "A number expressing a part of a whole or a ratio of two integers, written as a numerator over a denominator, such as three quarters; fractions represent rational numbers, are taught as a foundation of arithmetic, and appear as proper, improper and mixed forms, in unit subdivisions such as monetary subunits, and in notation across mathematics.",
    "what_it_is_for": "Expressing parts and ratios exactly.",
    "affordances": [
      "explain notation and kinds of fraction",
      "perform and explain fraction arithmetic",
      "convert between fractions, decimals and percentages",
      "support teaching and common misconceptions"
    ],
    "distinguishing_features": [
      "Exact representation of ratios",
      "Notation distinct from value",
      "Equivalent forms with different denominators",
      "Foundation of arithmetic"
    ],
    "appearance": "Not visible in itself; written as one number over another with a bar or slash.",
    "visual_identification": [
      "Numerator over denominator",
      "Proper, improper and mixed forms",
      "A ratio, a decimal and a percentage express related ideas differently"
    ],
    "physical_properties": [],
    "families_and_kinds": [
      "proper and improper fractions",
      "mixed numbers",
      "unit fractions",
      "equivalent and simplified fractions",
      "continued fractions and generating fractions",
      "fractions in units such as monetary subunits"
    ],
    "related_models": [
      {
        "relation": "is a kind of",
        "target": "mathematical notation",
        "why": "a way of writing numbers"
      },
      {
        "relation": "represents",
        "target": "rational number",
        "why": "the value"
      },
      {
        "relation": "is related to",
        "target": "decimal",
        "why": "another representation"
      },
      {
        "relation": "is related to",
        "target": "ratio",
        "why": "a comparison of quantities"
      }
    ],
    "identifiers": [],
    "standards_and_regulation": [
      "Mathematics curricula and standards for teaching fractions",
      "ISO 80000-2 notation conventions"
    ],
    "failure_modes_and_hazards": [
      "Adding numerators and denominators separately",
      "Confusing fraction notation with division or ratio contexts",
      "Rounding errors when converting to decimals"
    ],
    "in_scope": [],
    "out_of_scope": [],
    "characteristics": [],
    "agent_conduct": {
      "may": [
        "Compute with fractions and show the working step by step.",
        "Explain proper, improper and mixed forms and how to convert between them."
      ],
      "must_not": [
        "Add numerators and denominators separately or teach that as valid.",
        "Round a fraction to a decimal in a result without saying so.",
        "Give a learner only the answer when the task is to learn the method.",
        "Mark a correct but differently written fraction as wrong."
      ],
      "requires_human": [
        "Grading a learner's work where marks have consequences."
      ]
    },
    "ethics": {
      "considerations": [
        "Fractions are a gateway topic; poor teaching can turn learners away from mathematics."
      ],
      "affected_parties": [
        "Learners",
        "Teachers and parents"
      ]
    },
    "owners": {
      "steward": "Nobody owns the concept; it belongs to the shared body of mathematics.",
      "master_systems": []
    }
  },
  "sources": [
    {
      "id": "wikidata",
      "title": "Wikidata item Q66055: fraction",
      "url": "https://www.wikidata.org/wiki/Q66055",
      "url_status": "live",
      "what_it_supports": "identity and sense of the item",
      "checked_by": "wikidata-api"
    },
    {
      "id": "wikipedia-en",
      "title": "Wikipedia: Fraction",
      "url": "https://en.wikipedia.org/wiki/Fraction",
      "url_status": "live",
      "what_it_supports": "general description of the item",
      "checked_by": "wikidata-api sitelink"
    }
  ],
  "structure": {
    "bundles": [
      {
        "id": "concept",
        "name": "Concept",
        "description": "What a fraction is.",
        "rationale": "Definition.",
        "layers": [
          {
            "id": "definition",
            "name": "Definition",
            "description": "Definition.",
            "findings": [
              {
                "id": "definition-finding",
                "name": "Definition",
                "description": "Definition.",
                "questions": [
                  {
                    "text": "What does a fraction represent, and how do numerator and denominator work?",
                    "kind": "definition"
                  },
                  {
                    "text": "Is the question about fraction notation, rational numbers or ratios?",
                    "kind": "boundary"
                  }
                ]
              }
            ]
          },
          {
            "id": "kinds",
            "name": "Kinds",
            "description": "Kinds.",
            "findings": [
              {
                "id": "kinds-finding",
                "name": "Kinds",
                "description": "Kinds.",
                "questions": [
                  {
                    "text": "What kinds of fractions exist, and how are they converted between forms?",
                    "kind": "definition"
                  },
                  {
                    "text": "Which entry fits rational numbers?",
                    "kind": "action"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "compute",
        "name": "Compute",
        "description": "Arithmetic.",
        "rationale": "Computation.",
        "layers": [
          {
            "id": "operations",
            "name": "Operations",
            "description": "Operations.",
            "findings": [
              {
                "id": "operations-finding",
                "name": "Operations",
                "description": "Operations.",
                "questions": [
                  {
                    "text": "How are fractions added, subtracted, multiplied, divided and simplified?",
                    "kind": "action"
                  },
                  {
                    "text": "What is the result for the calculation in question?",
                    "kind": "measurement"
                  }
                ]
              }
            ]
          },
          {
            "id": "conversion",
            "name": "Conversion",
            "description": "Conversion.",
            "findings": [
              {
                "id": "conversion-finding",
                "name": "Conversion",
                "description": "Conversion.",
                "questions": [
                  {
                    "text": "How are fractions converted to decimals and percentages, and when is exactness lost?",
                    "kind": "action"
                  },
                  {
                    "text": "Which entry fits decimals?",
                    "kind": "action"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "learn",
        "name": "Learn",
        "description": "Teaching.",
        "rationale": "Education.",
        "layers": [
          {
            "id": "teaching",
            "name": "Teaching",
            "description": "Teaching fractions.",
            "findings": [
              {
                "id": "teaching-finding",
                "name": "Teaching",
                "description": "Teaching.",
                "questions": [
                  {
                    "text": "How are fractions taught, and which models and representations help?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which references are standard?",
                    "kind": "provenance"
                  }
                ]
              }
            ]
          },
          {
            "id": "misconceptions",
            "name": "Misconceptions",
            "description": "Misconceptions.",
            "findings": [
              {
                "id": "misconceptions-finding",
                "name": "Misconceptions",
                "description": "Misconceptions.",
                "questions": [
                  {
                    "text": "Which misconceptions are common, and how are they addressed?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which entry fits mathematics education?",
                    "kind": "action"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "context",
        "name": "Context",
        "description": "History and uses.",
        "rationale": "Context.",
        "layers": [
          {
            "id": "history",
            "name": "History",
            "description": "History.",
            "findings": [
              {
                "id": "history-finding",
                "name": "History",
                "description": "History.",
                "questions": [
                  {
                    "text": "How did fraction notation develop from Egyptian unit fractions to modern notation?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which entry fits the history of mathematics?",
                    "kind": "action"
                  }
                ]
              }
            ]
          },
          {
            "id": "uses",
            "name": "Uses",
            "description": "Uses.",
            "findings": [
              {
                "id": "uses-finding",
                "name": "Uses",
                "description": "Uses.",
                "questions": [
                  {
                    "text": "How are fractions used in measurement, music, finance and units?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which entry fits a specific use?",
                    "kind": "action"
                  }
                ]
              }
            ]
          }
        ]
      }
    ]
  },
  "openQuestions": [
    "Should rational number be the primary entry?",
    "How should curricula be linked?",
    "The registry entry has merged aliases for monetary subunits; should they be split off?"
  ],
  "statistics": {
    "bundles": 4,
    "layers": 8,
    "findings": 8,
    "questions": 16
  }
}