{
  "id": "math.fractions.part-to-part",
  "uri": "https://open-misconceptions.github.io/miscon-data/m/math.fractions.part-to-part",
  "uuid": "15a57c88-bbde-47b3-bd0d-6771a62e6cec",
  "version": "0.1.1",
  "status": "draft",
  "trust": "low",
  "title": "Writing the shaded part over the unshaded part",
  "statement": "A fraction compares the shaded part with the unshaded part, so the number of shaded pieces goes on top and the number of unshaded pieces goes underneath.",
  "kind": "notation-confusion",
  "domain": "math.fractions",
  "about": [
    {
      "scheme": "CCSS",
      "code": "3.NF.A.1",
      "uri": "http://corestandards.org/Math/Content/3/NF/A/1/"
    }
  ],
  "level_band": [
    "early-primary",
    "primary"
  ],
  "locale": "en",
  "evidence_patterns": [
    {
      "item_shape": "name the fraction shaded in a shape divided into equal parts",
      "signature": "writes shaded/unshaded instead of shaded/total",
      "example": {
        "item": "A bar is cut into 5 equal parts and 3 are shaded. What fraction is shaded?",
        "expected": "3/5",
        "response": "3/2"
      }
    }
  ],
  "discriminators": {
    "vs_slip": "Consistent across items, and the learner produces 'fractions' larger than one for a majority-shaded shape without noticing. A slip is one miswritten denominator.",
    "vs": {
      "math.fractions.unequal-parts": "Unequal-parts believers write the correct denominator (the total count) on equal-parts shapes; part-to-part writers do not."
    }
  },
  "relations": {
    "conflicts_with": [
      {
        "external": "http://corestandards.org/Math/Content/3/NF/A/1/",
        "label": "CCSS 3.NF.A.1: understand a fraction 1/b as one part of a whole partitioned into b equal parts"
      }
    ],
    "resolved_by": [
      {
        "external": "http://corestandards.org/Math/Content/3/NF/A/1/",
        "label": "CCSS 3.NF.A.1: understand a fraction 1/b as one part of a whole partitioned into b equal parts"
      }
    ],
    "confusable_with": [
      "math.fractions.unequal-parts"
    ]
  },
  "alignments": [
    {
      "scheme": "CCSS",
      "code": "3.NF.A.1",
      "uri": "http://corestandards.org/Math/Content/3/NF/A/1/",
      "relation": "about"
    }
  ],
  "provenance": {
    "sources": [
      {
        "type": "book",
        "citation": "Hart, K. M. (Ed.). (1981). Children's Understanding of Mathematics: 11-16. John Murray. (Concepts in Secondary Mathematics and Science project.)",
        "note": "CSMS fractions items: part-part responses on shaded-region tasks."
      },
      {
        "type": "book",
        "citation": "Kerslake, D. (1986). Fractions: Children's Strategies and Errors. NFER-Nelson."
      },
      {
        "type": "book",
        "citation": "Lamon, S. J. (2012). Teaching Fractions and Ratios for Understanding: Essential Content Knowledge and Instructional Strategies for Teachers (3rd ed.). Routledge.",
        "note": "Distinguishes part-whole from ratio (part-part) interpretations."
      }
    ],
    "origin": "llm-drafted",
    "notes": "Drafted from the cited literature for the Open Misconceptions seed pack; statement, examples and discriminators are original text. Awaiting maintainer review."
  },
  "history": {
    "changelog": [
      {
        "version": "0.1.1",
        "date": "2026-09-05",
        "change": "Schema 0.2 migration: about/alignments carry a free-string scheme (corestandards.org URLs relabelled CCSS where present); trust computed from reviews[] (none yet, so low); no change to the statement or evidence."
      }
    ]
  },
  "license": "CC-BY-4.0"
}