{
  "title": "Measure with a ruler activity",
  "human_url": "https://happytails.ai/en/education-tools/measure-with-a-ruler-activity/",
  "agent_url": "https://happytails.ai/agents/en/education-tools/measure-with-a-ruler-activity/",
  "language": "en",
  "markdown_url": "https://happytails.ai/en/education-tools/measure-with-a-ruler-activity.md",
  "content": "Measure with a ruler activity\nCreate true-scale measurement lines with an answer key and 100 mm and 1 in calibration bars.\nHow to use Measure with a ruler activity\nChoose millimetres, centimetres or an inch fraction, then set the measurement range.\nChoose the number of lines, paper size and seed.\nGenerate, then download the PDF and SVG worksheets, answer-key CSV and JSON report.\nPrint at 100% actual size with page scaling off and measure the 100 mm and 1 in calibration bars.\nHow can we improve this tool?\nReport a problem or share an idea.\nPlease leave out private information. Your message and the tool name go to our team via PostHog.\nUseful next steps\nPrintable paper generator\nUp to 16 measurement lines on A4 or US Letter. Lengths are bounded by the selected unit and page layout. Print at 100% actual size with page scaling off, then measure both calibration bars. Printer scaling and physical output are not verified by the tool.\nPrint scale\nThe worksheet geometry is generated in millimetres. Printer settings can scale the page, so select 100% actual size with page scaling off.\nCheck calibration\nMeasure the printed 100 mm and 1 in bars before using the worksheet. The browser cannot verify printer output.\nRepeat a worksheet\nA seed reproduces the same measurement lengths. The answer key is available separately as CSV.",
  "content_format": "text/plain",
  "visibility": "public",
  "links": [
    {
      "name": "Printable paper generator",
      "url": "https://happytails.ai/en/education-tools/printable-paper-generator/"
    }
  ],
  "tool": {
    "id": "measure-with-a-ruler-activity",
    "category": "education-tools",
    "built": true,
    "requirements": "Up to 16 measurement lines on A4 or US Letter. Lengths are bounded by the selected unit and page layout. Print at 100% actual size with page scaling off, then measure both calibration bars. Printer scaling and physical output are not verified by the tool.",
    "implementation": {
      "fields": [
        {
          "key": "unit",
          "label": "Measurement scale",
          "value": "cm",
          "type": "select",
          "values": [
            "mm",
            "cm",
            "cm-half",
            "in-half",
            "in-quarter",
            "in-eighth"
          ],
          "labels": {
            "mm": "Millimetres (1 mm steps)",
            "cm": "Centimetres (1 cm steps)",
            "cm-half": "Centimetres (0.5 cm steps)",
            "in-half": "Inches (1/2 in steps)",
            "in-quarter": "Inches (1/4 in steps)",
            "in-eighth": "Inches (1/8 in steps)"
          }
        },
        {
          "key": "count",
          "label": "Number of measurement lines",
          "value": 8,
          "type": "number",
          "min": 1,
          "max": 16,
          "step": 1
        },
        {
          "key": "minLength",
          "label": "Shortest length",
          "value": 2,
          "type": "text",
          "maxLength": 20,
          "help": "A whole number, decimal or fraction in the selected unit."
        },
        {
          "key": "maxLength",
          "label": "Longest length",
          "value": 15,
          "type": "text",
          "maxLength": 20,
          "help": "A whole number, decimal or fraction in the selected unit."
        },
        {
          "key": "paper",
          "label": "Paper size",
          "value": "A4",
          "type": "select",
          "values": [
            "A4",
            "Letter"
          ]
        },
        {
          "key": "seed",
          "label": "Seed",
          "value": 1,
          "type": "number",
          "min": 1,
          "max": 4294967295,
          "step": 1
        }
      ],
      "registrationFamily": "learning-activities-reference",
      "input": false,
      "presentation": "metrics",
      "note": "Create true-scale measurement lines with answer key, PDF and SVG, plus 100 mm and 1 in calibration bars. Print at 100% (actual size) with page scaling off, then check both bars. Printer scale cannot be verified here.",
      "example": {
        "input": "",
        "options": {
          "unit": "cm",
          "count": "4",
          "minLength": "2",
          "maxLength": "8",
          "paper": "A4",
          "seed": "1"
        }
      },
      "experience": {
        "automatic": false,
        "single": false,
        "inputMaxLength": 1000000,
        "inputMode": "text",
        "label": "Your text",
        "placeholder": "Type or paste your input…",
        "help": "Up to 1,000,000 characters. Review the settings before running.",
        "helpParts": [
          "Up to 1,000,000 characters.",
          "Review the settings before running."
        ],
        "action": null
      },
      "mode": "explicit",
      "interactive": false
    },
    "execution": "Browser interface",
    "api": null,
    "browser_agent": {
      "supported": true,
      "name": "run_current_tool",
      "discovery": "WebMCP on the human page in a supporting browser",
      "verification": "See audit/API-AUDIT.md; availability is not verification"
    }
  },
  "markdown": "# Measure with a ruler activity\n\n- Human page: https://happytails.ai/en/education-tools/measure-with-a-ruler-activity/\n- Markdown: https://happytails.ai/en/education-tools/measure-with-a-ruler-activity.md\n- Structured JSON: https://happytails.ai/agents/en/education-tools/measure-with-a-ruler-activity/index.json\n- Visibility: public\n\n## Tool capabilities\n\n| Property | Value |\n| --- | --- |\n| Tool ID | `measure-with-a-ruler-activity` |\n| Category | education-tools |\n| Implementation | Registered implementation. Registration alone is not a production-quality guarantee. |\n| Browser execution | Use the visible action or interactive controls. |\n| Browser processing | Browser; see tool notes for network behavior. |\n| HTTP API | Not callable through HTTP. |\n| Browser-agent interface | run_current_tool |\n\n### Implementation notes\n\nCreate true-scale measurement lines with answer key, PDF and SVG, plus 100 mm and 1 in calibration bars. Print at 100% (actual size) with page scaling off, then check both bars. Printer scale cannot be verified here.\n\n### Inputs and settings\n\nNo free-text input is required. Use the file inputs and/or settings below.\n\n| Setting | Meaning | Control type | Default | Constraints |\n| --- | --- | --- | --- | --- |\n| `unit` | Measurement scale | select | \"cm\" | Allowed: mm, cm, cm-half, in-half, in-quarter, in-eighth |\n| `count` | Number of measurement lines | number | 8 | min=1 max=16 step=1 |\n| `minLength` | Shortest length | text | 2 |  |\n| `maxLength` | Longest length | text | 15 |  |\n| `paper` | Paper size | select | \"A4\" | Allowed: A4, Letter |\n| `seed` | Seed | number | 1 | min=1 max=4294967295 step=1 |\n\n### Browser-agent workflow\n\n1. Open the human page in a browser that supports WebMCP.\n2. Discover the interface exposed by that page; use its actual schema.\n3. Select files on the page first when the tool requires files.\n4. Call `run_current_tool` with valid input and settings.\n5. Inspect the returned result or error and the displayed output. Retrieve files from the displayed download links.\n\nCalls do not automatically copy or download results. Browser permissions still apply. Interface availability alone is not proof of successful execution.\n\n### Planning specification\n\nUp to 16 measurement lines on A4 or US Letter. Lengths are bounded by the selected unit and page layout. Print at 100% actual size with page scaling off, then measure both calibration bars. Printer scaling and physical output are not verified by the tool.\n\nThis describes intended requirements. Use the implementation notes, interface schema and observed output to determine current support.\n\n### Complete machine-readable capability record\n\n```json\n{\n  \"id\": \"measure-with-a-ruler-activity\",\n  \"category\": \"education-tools\",\n  \"built\": true,\n  \"requirements\": \"Up to 16 measurement lines on A4 or US Letter. Lengths are bounded by the selected unit and page layout. Print at 100% actual size with page scaling off, then measure both calibration bars. Printer scaling and physical output are not verified by the tool.\",\n  \"implementation\": {\n    \"fields\": [\n      {\n        \"key\": \"unit\",\n        \"label\": \"Measurement scale\",\n        \"value\": \"cm\",\n        \"type\": \"select\",\n        \"values\": [\n          \"mm\",\n          \"cm\",\n          \"cm-half\",\n          \"in-half\",\n          \"in-quarter\",\n          \"in-eighth\"\n        ],\n        \"labels\": {\n          \"mm\": \"Millimetres (1 mm steps)\",\n          \"cm\": \"Centimetres (1 cm steps)\",\n          \"cm-half\": \"Centimetres (0.5 cm steps)\",\n          \"in-half\": \"Inches (1/2 in steps)\",\n          \"in-quarter\": \"Inches (1/4 in steps)\",\n          \"in-eighth\": \"Inches (1/8 in steps)\"\n        }\n      },\n      {\n        \"key\": \"count\",\n        \"label\": \"Number of measurement lines\",\n        \"value\": 8,\n        \"type\": \"number\",\n        \"min\": 1,\n        \"max\": 16,\n        \"step\": 1\n      },\n      {\n        \"key\": \"minLength\",\n        \"label\": \"Shortest length\",\n        \"value\": 2,\n        \"type\": \"text\",\n        \"maxLength\": 20,\n        \"help\": \"A whole number, decimal or fraction in the selected unit.\"\n      },\n      {\n        \"key\": \"maxLength\",\n        \"label\": \"Longest length\",\n        \"value\": 15,\n        \"type\": \"text\",\n        \"maxLength\": 20,\n        \"help\": \"A whole number, decimal or fraction in the selected unit.\"\n      },\n      {\n        \"key\": \"paper\",\n        \"label\": \"Paper size\",\n        \"value\": \"A4\",\n        \"type\": \"select\",\n        \"values\": [\n          \"A4\",\n          \"Letter\"\n        ]\n      },\n      {\n        \"key\": \"seed\",\n        \"label\": \"Seed\",\n        \"value\": 1,\n        \"type\": \"number\",\n        \"min\": 1,\n        \"max\": 4294967295,\n        \"step\": 1\n      }\n    ],\n    \"registrationFamily\": \"learning-activities-reference\",\n    \"input\": false,\n    \"presentation\": \"metrics\",\n    \"note\": \"Create true-scale measurement lines with answer key, PDF and SVG, plus 100 mm and 1 in calibration bars. Print at 100% (actual size) with page scaling off, then check both bars. Printer scale cannot be verified here.\",\n    \"example\": {\n      \"input\": \"\",\n      \"options\": {\n        \"unit\": \"cm\",\n        \"count\": \"4\",\n        \"minLength\": \"2\",\n        \"maxLength\": \"8\",\n        \"paper\": \"A4\",\n        \"seed\": \"1\"\n      }\n    },\n    \"experience\": {\n      \"automatic\": false,\n      \"single\": false,\n      \"inputMaxLength\": 1000000,\n      \"inputMode\": \"text\",\n      \"label\": \"Your text\",\n      \"placeholder\": \"Type or paste your input…\",\n      \"help\": \"Up to 1,000,000 characters. Review the settings before running.\",\n      \"helpParts\": [\n        \"Up to 1,000,000 characters.\",\n        \"Review the settings before running.\"\n      ],\n      \"action\": null\n    },\n    \"mode\": \"explicit\",\n    \"interactive\": false\n  },\n  \"execution\": \"Browser interface\",\n  \"api\": null,\n  \"browser_agent\": {\n    \"supported\": true,\n    \"name\": \"run_current_tool\",\n    \"discovery\": \"WebMCP on the human page in a supporting browser\",\n    \"verification\": \"See audit/API-AUDIT.md; availability is not verification\"\n  }\n}\n```\n\n## Page guide\n\nCreate true-scale measurement lines with an answer key and 100 mm and 1 in calibration bars.\n\n### How to use Measure with a ruler activity\n\n1. Choose millimetres, centimetres or an inch fraction, then set the measurement range.\n2. Choose the number of lines, paper size and seed.\n3. Generate, then download the PDF and SVG worksheets, answer-key CSV and JSON report.\n4. Print at 100% actual size with page scaling off and measure the 100 mm and 1 in calibration bars.\n\nHow can we improve this tool?\n\nReport a problem or share an idea.\n\nPlease leave out private information. Your message and the tool name go to our team via PostHog.\n\n## Useful next steps\n\n- [Printable paper generator](https://happytails.ai/en/education-tools/printable-paper-generator/) ([Markdown](https://happytails.ai/en/education-tools/printable-paper-generator.md))\n\nUp to 16 measurement lines on A4 or US Letter. Lengths are bounded by the selected unit and page layout. Print at 100% actual size with page scaling off, then measure both calibration bars. Printer scaling and physical output are not verified by the tool.\n\n## Print scale\n\nThe worksheet geometry is generated in millimetres. Printer settings can scale the page, so select 100% actual size with page scaling off.\n\n### Check calibration\n\nMeasure the printed 100 mm and 1 in bars before using the worksheet. The browser cannot verify printer output.\n\n### Repeat a worksheet\n\nA seed reproduces the same measurement lengths. The answer key is available separately as CSV.\n"
}