<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      background: #ffffff;
      color: #1e293b;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
      padding: 12px 16px;
      user-select: none;
    }

    .main-wrapper {
      width: 100%;
      max-width: 580px;
      display: flex;
      flex-direction: column;
      gap: 18px;
    }

    /* Ratio Table Container */
    .table-container {
      position: relative;
      width: 100%;
      padding-top: 38px;
      padding-bottom: 38px;
    }

    /* Grid Table */
    .ratio-table {
      display: grid;
      grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
      border: 2px solid #cbd5e1;
      border-radius: 12px;
      background: #ffffff;
      overflow: hidden;
      box-shadow: 0 4px 12px rgba(15, 23, 42, 0.04);
    }

    .cell {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      padding: 10px 6px;
      border-bottom: 1px solid #e2e8f0;
      border-right: 1px solid #e2e8f0;
      font-variant-numeric: tabular-nums;
      text-align: center;
    }
    .cell:nth-child(4n) {
      border-right: none;
    }
    .cell:nth-child(n+5) {
      border-bottom: none;
    }

    .row-header {
      background: #f8fafc;
      font-weight: 700;
      font-size: 14px;
      color: #475569;
      text-align: left;
      align-items: flex-start;
      padding-left: 12px;
    }
    .row-header span {
      font-size: 12px;
      font-weight: 500;
      color: #64748b;
    }

    .val-cell {
      font-size: 17px;
      font-weight: 700;
      color: #0f172a;
      transition: background 0.3s ease, color 0.3s ease;
    }
    .val-cell.col-1 {
      background: #f0fdf4;
      color: #15803d;
    }
    .val-cell.col-2 {
      background: #f8fafc;
    }
    .val-cell.col-3 {
      background: #eff6ff;
      color: #1d4ed8;
    }

    /* SVG Overlay for curved arrows */
    .arrows-svg {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      pointer-events: none;
      overflow: visible;
    }

    .arrow-path {
      fill: none;
      stroke-width: 2;
      stroke-linecap: round;
    }
    .arrow-blue {
      stroke: #2563eb;
    }
    .arrow-purple {
      stroke: #7c3aed;
    }
    .arrow-label {
      font-size: 12px;
      font-weight: 800;
      paint-order: stroke;
      stroke: #ffffff;
      stroke-width: 3px;
      stroke-linecap: round;
      stroke-linejoin: round;
    }
    .label-blue {
      fill: #2563eb;
    }
    .label-purple {
      fill: #7c3aed;
    }

    /* Unit Rate Tag */
    .badge {
      display: inline-block;
      font-size: 10px;
      font-weight: 800;
      text-transform: uppercase;
      letter-spacing: 0.5px;
      padding: 2px 6px;
      border-radius: 4px;
      margin-top: 2px;
      background: #dcfce7;
      color: #166534;
    }

    /* Equation Section */
    .equation-card {
      background: #f8fafc;
      border: 1.5px solid #e2e8f0;
      border-radius: 12px;
      padding: 14px 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 8px;
    }

    .equation-title {
      font-size: 12px;
      font-weight: 700;
      color: #64748b;
      text-transform: uppercase;
      letter-spacing: 0.8px;
    }

    .equation-row {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      font-size: 17px;
      font-weight: 700;
      color: #0f172a;
      flex-wrap: nowrap;
    }

    .fraction {
      display: inline-flex;
      flex-direction: column;
      align-items: center;
      vertical-align: middle;
      padding: 0 4px;
    }
    .num {
      border-bottom: 2px solid #0f172a;
      padding-bottom: 2px;
      text-align: center;
      width: 100%;
    }
    .den {
      padding-top: 2px;
      text-align: center;
      width: 100%;
    }

    /* Unit Strike-through */
    .slash-unit {
      position: relative;
      display: inline-block;
      color: #64748b;
      font-weight: 600;
    }
    .slash-unit::after {
      content: "";
      position: absolute;
      left: -2px;
      top: 50%;
      width: calc(100% + 4px);
      height: 2px;
      background: #ef4444;
      transform: translateY(-50%) rotate(-25deg);
      border-radius: 1px;
    }

    .target-val {
      color: #1d4ed8;
      font-weight: 800;
      background: #dbeafe;
      padding: 2px 8px;
      border-radius: 6px;
    }

    @media (max-width: 420px) {
      .row-header {
        font-size: 12px;
        padding-left: 6px;
      }
      .row-header span {
        font-size: 10px;
      }
      .val-cell {
        font-size: 14px;
      }
      .badge {
        font-size: 9px;
        padding: 1px 4px;
      }
      .equation-row {
        font-size: 14px;
        gap: 6px;
      }
    }
  </style>
</head>
<body>

  <div class="main-wrapper">
    
    <div class="table-container" id="tableContainer">
      <svg class="arrows-svg" viewBox="0 0 540 160" preserveAspectRatio="none">
        <defs>
          
          <marker id="arrow-blue" viewBox="0 0 10 10" refX="6" refY="5" markerWidth="6" markerHeight="6" orient="auto-start-reverse">
            <path d="M 0 1 L 8 5 L 0 9 z" fill="#2563eb" />
          </marker>
          
          <marker id="arrow-purple" viewBox="0 0 10 10" refX="6" refY="5" markerWidth="6" markerHeight="6" orient="auto-start-reverse">
            <path d="M 0 1 L 8 5 L 0 9 z" fill="#7c3aed" />
          </marker>
        </defs>

        
        <path class="arrow-path arrow-blue" marker-end="url(#arrow-blue)" d="M 205 38 C 225 10, 275 10, 295 38" />
        <text x="250" y="17" text-anchor="middle" class="arrow-label label-blue">× 2</text>

        
        <path class="arrow-path arrow-purple" marker-end="url(#arrow-purple)" d="M 215 34 C 270 -16, 400 -16, 445 34" />
        <text x="330" y="2" text-anchor="middle" class="arrow-label label-purple">× 4.5</text>

        
        <path class="arrow-path arrow-blue" marker-end="url(#arrow-blue)" d="M 205 122 C 225 150, 275 150, 295 122" />
        <text x="250" y="152" text-anchor="middle" class="arrow-label label-blue">× 2</text>

        
        <path class="arrow-path arrow-purple" marker-end="url(#arrow-purple)" d="M 215 126 C 270 176, 400 176, 445 126" />
        <text x="330" y="165" text-anchor="middle" class="arrow-label label-purple">× 4.5</text>
      </svg>

      <div class="ratio-table">
        
        <div class="cell row-header">
          Kilometers
          <span>(km)</span>
        </div>
        <div class="cell val-cell col-1">
          1
          <span class="badge">Unit Rate</span>
        </div>
        <div class="cell val-cell col-2">2</div>
        <div class="cell val-cell col-3">4.5</div>

        
        <div class="cell row-header">
          Meters
          <span>(m)</span>
        </div>
        <div class="cell val-cell col-1">1,000</div>
        <div class="cell val-cell col-2">2,000</div>
        <div class="cell val-cell col-3">4,500</div>
      </div>
    </div>

    
    <div class="equation-card">
      <div class="equation-title">Unit Factor Conversion</div>
      <div class="equation-row">
        <span>4.5 <span class="slash-unit">km</span></span>
        <span>×</span>
        <div class="fraction">
          <span class="num">1,000 m</span>
          <span class="den">1 <span class="slash-unit">km</span></span>
        </div>
        <span>=</span>
        <span class="target-val">4,500 m</span>
      </div>
    </div>
  </div>

</body>
</html>

Converting Metric Units Using Ratio Reasoning

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <title>Metric Ratio Reasoning</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
      color: #1e293b;
      background: transparent;
      padding: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 12px;
    }

    /* Top Badge */
    .header-badge {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      padding: 6px 14px;
      background: #f1f5f9;
      border: 1px solid #cbd5e1;
      border-radius: 9999px;
      font-size: 13px;
      font-weight: 700;
      color: #334155;
      letter-spacing: 0.2px;
    }
    .badge-highlight {
      color: #4f46e5;
      background: #e0e7ff;
      padding: 2px 8px;
      border-radius: 6px;
      font-weight: 800;
    }

    /* Columns Container */
    .grid-container {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 12px;
      width: 100%;
      max-width: 680px;
    }

    @media (max-width: 520px) {
      .grid-container {
        grid-template-columns: 1fr;
      }
    }

    /* Column Card */
    .column-box {
      background: #ffffff;
      border-radius: 12px;
      padding: 12px;
      border: 1px solid #e2e8f0;
      display: flex;
      flex-direction: column;
      gap: 10px;
      position: relative;
    }

    .box-mass {
      border-top: 4px solid #4f46e5;
    }
    .box-cap {
      border-top: 4px solid #0284c7;
    }

    /* Header with Icon */
    .box-header {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 15px;
      font-weight: 700;
    }
    .box-mass .box-header { color: #4338ca; }
    .box-cap .box-header { color: #0369a1; }

    .icon-wrap {
      display: flex;
      align-items: center;
      justify-content: center;
      width: 28px;
      height: 28px;
      border-radius: 6px;
    }
    .box-mass .icon-wrap { background: #e0e7ff; }
    .box-cap .icon-wrap { background: #e0f2fe; }

    /* Interactive Table Area */
    .table-wrapper {
      position: relative;
      margin-left: 48px; /* space for vertical multiplier arrow */
      margin-top: 24px;  /* space for horizontal multiplier arrow */
    }

    /* Horizontal conversion arrow */
    .h-arrow-wrap {
      position: absolute;
      top: -24px;
      left: 10%;
      width: 80%;
      height: 20px;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .h-arrow-line {
      position: absolute;
      width: 100%;
      height: 2px;
      top: 14px;
    }
    .box-mass .h-arrow-line { background: #4f46e5; }
    .box-cap .h-arrow-line { background: #0284c7; }

    .h-arrow-head {
      position: absolute;
      right: -2px;
      top: 10px;
      width: 0;
      height: 0;
      border-top: 5px solid transparent;
      border-bottom: 5px solid transparent;
    }
    .box-mass .h-arrow-head { border-left: 7px solid #4f46e5; }
    .box-cap .h-arrow-head { border-left: 7px solid #0284c7; }

    .h-arrow-label {
      position: absolute;
      top: -2px;
      background: #ffffff;
      padding: 0 6px;
      font-size: 11px;
      font-weight: 800;
      border-radius: 4px;
    }
    .box-mass .h-arrow-label { color: #4338ca; border: 1px solid #c7d2fe; }
    .box-cap .h-arrow-label { color: #0369a1; border: 1px solid #bae6fd; }

    /* Vertical scaling arrow */
    .v-arrow-wrap {
      position: absolute;
      left: -44px;
      top: 36px;
      height: 60px;
      width: 40px;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .v-arrow-svg {
      width: 100%;
      height: 100%;
      overflow: visible;
    }
    .v-arrow-label {
      position: absolute;
      left: -2px;
      top: 20px;
      font-size: 11px;
      font-weight: 800;
      background: #ffffff;
      padding: 1px 4px;
      border-radius: 4px;
      white-space: nowrap;
    }
    .box-mass .v-arrow-label { color: #4338ca; border: 1px solid #c7d2fe; }
    .box-cap .v-arrow-label { color: #0369a1; border: 1px solid #bae6fd; }

    /* Ratio Table */
    .ratio-table {
      width: 100%;
      border-collapse: separate;
      border-spacing: 0;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      overflow: hidden;
      font-size: 13px;
      text-align: center;
    }
    .ratio-table th {
      padding: 6px 4px;
      background: #f8fafc;
      font-weight: 700;
      color: #475569;
      border-bottom: 1px solid #e2e8f0;
      width: 50%;
    }
    .ratio-table th:first-child {
      border-right: 1px solid #e2e8f0;
    }
    .ratio-table td {
      padding: 8px 4px;
      font-weight: 600;
      color: #1e293b;
    }
    .ratio-table tr:first-child td {
      background: #ffffff;
      border-bottom: 1px dashed #e2e8f0;
    }
    .ratio-table tr:nth-child(2) td {
      background: #fcfcfd;
    }
    .ratio-table td:first-child {
      border-right: 1px solid #e2e8f0;
    }

    .unit-tag {
      font-size: 11px;
      font-weight: 500;
      color: #64748b;
      margin-left: 2px;
    }

    .box-mass .highlight-cell {
      background: #eef2ff !important;
      color: #3730a3;
      font-weight: 700;
    }
    .box-cap .highlight-cell {
      background: #f0f9ff !important;
      color: #075985;
      font-weight: 700;
    }

    /* Live Calculator Strip inside cards */
    .calc-row {
      display: flex;
      align-items: center;
      justify-content: space-between;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      padding: 6px 8px;
      margin-top: 4px;
      font-size: 12px;
    }
    .calc-input {
      width: 62px;
      padding: 3px 6px;
      font-size: 12px;
      font-weight: 700;
      border: 1px solid #cbd5e1;
      border-radius: 4px;
      text-align: right;
      color: #0f172a;
      background: #fff;
    }
    .calc-input:focus {
      outline: 2px solid #4f46e5;
      border-color: transparent;
    }
    .calc-result {
      font-weight: 800;
      padding: 2px 6px;
      border-radius: 4px;
    }
    .box-mass .calc-result { color: #4338ca; background: #e0e7ff; }
    .box-cap .calc-result { color: #0369a1; background: #e0f2fe; }

    /* Summary Bar */
    .summary-bar {
      width: 100%;
      max-width: 680px;
      background: #f8fafc;
      border: 1px solid #cbd5e1;
      border-radius: 8px;
      padding: 8px 12px;
      font-size: 12px;
      line-height: 1.4;
      text-align: center;
      color: #334155;
    }
    .summary-bar strong {
      color: #0f172a;
    }
  </style>
</head>
<body>

  
  <div class="header-badge">
    <span>Metric Ratio Structure:</span>
    <span class="badge-highlight">Base Multiplier &times; 1,000</span>
  </div>

  
  <div class="grid-container">

    
    <div class="column-box box-mass">
      <div class="box-header">
        <div class="icon-wrap">
          
          <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="#4f46e5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
            <line x1="12" y1="3" x2="12" y2="21"></line>
            <path d="M4 7l8-4 8 4"></path>
            <path d="M4 7l-2 8h8l-2-8"></path>
            <path d="M20 7l-2 8h8l-2-8"></path>
            <path d="M9 21h6"></path>
          </svg>
        </div>
        <span>Mass (kg &harr; g)</span>
      </div>

      <div class="table-wrapper">
        
        <div class="h-arrow-wrap">
          <div class="h-arrow-line"></div>
          <div class="h-arrow-head"></div>
          <div class="h-arrow-label">&times; 1,000</div>
        </div>

        
        <div class="v-arrow-wrap">
          <svg class="v-arrow-svg" viewBox="0 0 30 60">
            <path d="M 22 4 C 6 15, 6 45, 20 54" fill="none" stroke="#4f46e5" stroke-width="2" stroke-dasharray="3 2" />
            <polyline points="15,50 21,55 21,47" fill="none" stroke="#4f46e5" stroke-width="2" stroke-linecap="round" />
          </svg>
          <div class="v-arrow-label">&times; 0.75</div>
        </div>

        
        <table class="ratio-table">
          <thead>
            <tr>
              <th>Kilograms (kg)</th>
              <th>Grams (g)</th>
            </tr>
          </thead>
          <tbody>
            <tr>
              <td>1<span class="unit-tag">kg</span></td>
              <td>1,000<span class="unit-tag">g</span></td>
            </tr>
            <tr>
              <td class="highlight-cell">0.75<span class="unit-tag">kg</span></td>
              <td class="highlight-cell">750<span class="unit-tag">g</span></td>
            </tr>
          </tbody>
        </table>
      </div>

      
      <div class="calc-row">
        <label for="kgInput">Try:</label>
        <input type="number" id="kgInput" class="calc-input" value="0.75" step="0.25" min="0" />
        <span>kg =</span>
        <span id="gOutput" class="calc-result">750 g</span>
      </div>
    </div>

    
    <div class="column-box box-cap">
      <div class="box-header">
        <div class="icon-wrap">
          
          <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="#0284c7" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
            <path d="M6 3h12v3a6 6 0 0 1-6 6v0a6 6 0 0 1-6-6V3z" opacity="0.3"></path>
            <path d="M5 3h14"></path>
            <path d="M6 3v15a3 3 0 0 0 3 3h6a3 3 0 0 0 3-3V3"></path>
            <line x1="9" y1="9" x2="13" y2="9"></line>
            <line x1="9" y1="13" x2="15" y2="13"></line>
          </svg>
        </div>
        <span>Capacity (L &harr; mL)</span>
      </div>

      <div class="table-wrapper">
        
        <div class="h-arrow-wrap">
          <div class="h-arrow-line"></div>
          <div class="h-arrow-head"></div>
          <div class="h-arrow-label">&times; 1,000</div>
        </div>

        
        <div class="v-arrow-wrap">
          <svg class="v-arrow-svg" viewBox="0 0 30 60">
            <path d="M 22 4 C 6 15, 6 45, 20 54" fill="none" stroke="#0284c7" stroke-width="2" stroke-dasharray="3 2" />
            <polyline points="15,50 21,55 21,47" fill="none" stroke="#0284c7" stroke-width="2" stroke-linecap="round" />
          </svg>
          <div class="v-arrow-label">&times; 2.5</div>
        </div>

        
        <table class="ratio-table">
          <thead>
            <tr>
              <th>Liters (L)</th>
              <th>Milliliters (mL)</th>
            </tr>
          </thead>
          <tbody>
            <tr>
              <td>1<span class="unit-tag">L</span></td>
              <td>1,000<span class="unit-tag">mL</span></td>
            </tr>
            <tr>
              <td class="highlight-cell">2.5<span class="unit-tag">L</span></td>
              <td class="highlight-cell">2,500<span class="unit-tag">mL</span></td>
            </tr>
          </tbody>
        </table>
      </div>

      
      <div class="calc-row">
        <label for="lInput">Try:</label>
        <input type="number" id="lInput" class="calc-input" value="2.5" step="0.5" min="0" />
        <span>L =</span>
        <span id="mlOutput" class="calc-result">2,500 mL</span>
      </div>
    </div>

  </div>

  
  <div class="summary-bar">
    <strong>1 kg = 1,000 g</strong> &bull; <strong>1 L = 1,000 mL</strong><br>
    Multiply by <strong>1,000</strong> (large &rarr; small) &bull; Divide by <strong>1,000</strong> (small &rarr; large)
  </div>

  <script>
    const kgInput = document.getElementById('kgInput');
    const gOutput = document.getElementById('gOutput');
    const lInput = document.getElementById('lInput');
    const mlOutput = document.getElementById('mlOutput');

    function updateMass() {
      const val = parseFloat(kgInput.value);
      if (isNaN(val) || val < 0) {
        gOutput.textContent = '— g';
      } else {
        const grams = val * 1000;
        gOutput.textContent = grams.toLocaleString() + ' g';
      }
    }

    function updateCapacity() {
      const val = parseFloat(lInput.value);
      if (isNaN(val) || val < 0) {
        mlOutput.textContent = '— mL';
      } else {
        const ml = val * 1000;
        mlOutput.textContent = ml.toLocaleString() + ' mL';
      }
    }

    kgInput.addEventListener('input', updateMass);
    lInput.addEventListener('input', updateCapacity);
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      background: #ffffff;
      padding: 16px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
    }

    .diagram {
      width: 100%;
      max-width: 620px;
      display: flex;
      flex-direction: column;
      gap: 20px;
      align-items: center;
    }

    /* Flow Row */
    .flow-chain {
      display: flex;
      align-items: center;
      justify-content: center;
      flex-wrap: wrap;
      gap: 8px;
      width: 100%;
    }

    .node {
      background: #f8fafc;
      border: 2px solid #cbd5e1;
      border-radius: 12px;
      padding: 12px 14px;
      text-align: center;
      min-width: 110px;
      transition: all 0.3s ease;
    }

    .node .val {
      font-size: 18px;
      font-weight: 700;
      line-height: 1.2;
    }

    .node .unit {
      font-size: 13px;
      font-weight: 600;
      color: #64748b;
      margin-top: 2px;
    }

    .node.active {
      border-color: #22b7ff;
      background: #f0f9ff;
      box-shadow: 0 0 0 3px rgba(34, 183, 255, 0.25);
    }

    .node.result {
      border-color: #10b981;
      background: #ecfdf5;
      color: #065f46;
    }
    .node.result .unit {
      color: #047857;
    }
    .node.result.active {
      border-color: #10b981;
      box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.3);
    }

    /* Operation Connector */
    .connector {
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 4px 6px;
      opacity: 0.35;
      transition: opacity 0.3s ease;
    }
    .connector.active {
      opacity: 1;
    }

    .op-badge {
      background: #22b7ff;
      color: #ffffff;
      font-size: 13px;
      font-weight: 700;
      padding: 3px 8px;
      border-radius: 20px;
      white-space: nowrap;
      margin-bottom: 2px;
    }

    .arrow {
      font-size: 18px;
      color: #0284c7;
      font-weight: bold;
      line-height: 1;
    }

    /* Ratio Table */
    .table-container {
      width: 100%;
      background: #f8fafc;
      border-radius: 12px;
      border: 1px solid #e2e8f0;
      overflow: hidden;
    }

    table {
      width: 100%;
      border-collapse: collapse;
      text-align: center;
      font-size: 14px;
    }

    th {
      background: #f1f5f9;
      color: #475569;
      font-weight: 600;
      padding: 10px 8px;
      border-bottom: 1px solid #e2e8f0;
    }

    td {
      padding: 12px 8px;
      border-bottom: 1px solid #f1f5f9;
      font-variant-numeric: tabular-nums;
    }

    .col-highlight {
      background: rgba(34, 183, 255, 0.08);
      font-weight: 700;
    }
    .col-result {
      background: rgba(16, 185, 129, 0.1);
      font-weight: 700;
      color: #065f46;
    }

    /* Stepper Controls */
    .controls {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      width: 100%;
    }

    .step-btn {
      background: #ffffff;
      border: 1px solid #cbd5e1;
      border-radius: 8px;
      padding: 8px 14px;
      font-size: 13px;
      font-weight: 600;
      color: #475569;
      cursor: pointer;
      transition: all 0.2s ease;
    }

    .step-btn:hover {
      background: #f1f5f9;
      border-color: #94a3b8;
    }

    .step-btn.active {
      background: #22b7ff;
      border-color: #22b7ff;
      color: #ffffff;
    }

    .play-btn {
      background: #f8fafc;
      border: 1px solid #cbd5e1;
      border-radius: 8px;
      width: 36px;
      height: 36px;
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      font-size: 14px;
      color: #334155;
    }
  </style>
</head>
<body>
  <div class="diagram">
    
    <div class="flow-chain">
      <div class="node" id="n0">
        <div class="val">650,000</div>
        <div class="unit">cm</div>
      </div>

      <div class="connector" id="c1">
        <div class="op-badge">÷ 100</div>
        <div class="arrow">➔</div>
      </div>

      <div class="node" id="n1">
        <div class="val">6,500</div>
        <div class="unit">m</div>
      </div>

      <div class="connector" id="c2">
        <div class="op-badge">÷ 1,000</div>
        <div class="arrow">➔</div>
      </div>

      <div class="node result" id="n2">
        <div class="val">6.5</div>
        <div class="unit">km</div>
      </div>
    </div>

    
    <div class="table-container">
      <table>
        <thead>
          <tr>
            <th>Unit Stage</th>
            <th>Ratio Factor</th>
            <th>Value</th>
          </tr>
        </thead>
        <tbody>
          <tr id="tr0">
            <td>Centimeters (cm)</td>
            <td>Starting Value</td>
            <td class="col-highlight">650,000 cm</td>
          </tr>
          <tr id="tr1">
            <td>Meters (m)</td>
            <td>1 m = 100 cm</td>
            <td id="td1">6,500 m</td>
          </tr>
          <tr id="tr2">
            <td>Kilometers (km)</td>
            <td>1 km = 1,000 m</td>
            <td id="td2" class="col-result">6.5 km</td>
          </tr>
        </tbody>
      </table>
    </div>

    
    <div class="controls">
      <button class="step-btn active" data-step="0">Start (cm)</button>
      <button class="step-btn" data-step="1">Step 1 (÷100)</button>
      <button class="step-btn" data-step="2">Step 2 (÷1,000)</button>
      <button class="play-btn" id="playBtn" title="Auto Play">▶</button>
    </div>
  </div>

  <script>
    let currentStep = 0;
    let timer = null;

    const nodes = [
      document.getElementById('n0'),
      document.getElementById('n1'),
      document.getElementById('n2')
    ];
    const connectors = [
      document.getElementById('c1'),
      document.getElementById('c2')
    ];
    const rows = [
      document.getElementById('tr0'),
      document.getElementById('tr1'),
      document.getElementById('tr2')
    ];
    const stepBtns = document.querySelectorAll('.step-btn');
    const playBtn = document.getElementById('playBtn');

    function setStep(step) {
      currentStep = step;

      // Update buttons
      stepBtns.forEach((btn, idx) => {
        btn.classList.toggle('active', idx === step);
      });

      // Update flow chain nodes
      nodes.forEach((n, idx) => {
        n.classList.toggle('active', idx <= step);
      });

      // Update connectors
      connectors[0].classList.toggle('active', step >= 1);
      connectors[1].classList.toggle('active', step >= 2);

      // Update table row styling
      rows.forEach((r, idx) => {
        if (idx === step) {
          r.style.background = idx === 2 ? 'rgba(16, 185, 129, 0.08)' : 'rgba(34, 183, 255, 0.08)';
        } else {
          r.style.background = 'transparent';
        }
      });
    }

    stepBtns.forEach(btn => {
      btn.addEventListener('click', () => {
        stopAuto();
        setStep(parseInt(btn.dataset.step, 10));
      });
    });

    function toggleAuto() {
      if (timer) {
        stopAuto();
      } else {
        playBtn.textContent = '⏸';
        timer = setInterval(() => {
          setStep((currentStep + 1) % 3);
        }, 3200);
      }
    }

    function stopAuto() {
      if (timer) {
        clearInterval(timer);
        timer = null;
        playBtn.textContent = '▶';
      }
    }

    playBtn.addEventListener('click', toggleAuto);

    // Initialize initial state
    setStep(0);
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, sans-serif;
      background: #f8fafc;
      color: #0f172a;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
      padding: 12px 8px;
      user-select: none;
    }

    .header-nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 580px;
      margin-bottom: 6px;
      padding: 0 4px;
    }

    .dir-banner {
      display: flex;
      align-items: center;
      gap: 6px;
      font-size: 13px;
      font-weight: 700;
      color: #1e2945;
      background: #e2e8f0;
      padding: 4px 10px;
      border-radius: 20px;
    }
    .dir-banner.right { background: #dbeafe; color: #1e40af; }
    .dir-banner.left { background: #fef3c7; color: #92400e; }

    /* Ladder container */
    .ladder {
      display: flex;
      align-items: flex-end;
      justify-content: center;
      gap: 4px;
      width: 100%;
      max-width: 580px;
      height: 230px;
      padding: 8px 2px 2px 2px;
      position: relative;
    }

    /* Individual step */
    .step {
      flex: 1;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: flex-start;
      border-radius: 8px 8px 4px 4px;
      background: #e2e8f0;
      border: 2px solid transparent;
      padding: 6px 2px;
      cursor: pointer;
      transition: background 0.2s, box-shadow 0.2s, transform 0.2s;
      position: relative;
    }
    .step:hover {
      box-shadow: 0 0 0 2px #38bdf8;
    }

    /* Height progression (left higher, descending to right) */
    .s-kilo  { height: 100%; background: #bfdbfe; }
    .s-hecto { height: 86%;  background: #c7d2fe; }
    .s-deka  { height: 72%;  background: #ddd6fe; }
    .s-base  { height: 58%;  background: #38bdf8; color: #0f172a; font-weight: 700; }
    .s-deci  { height: 44%;  background: #e2e8f0; }
    .s-centi { height: 30%;  background: #e2e8f0; }
    .s-milli { height: 18%;  background: #e2e8f0; }

    .step.active {
      box-shadow: 0 0 0 3px #1e2945;
      background: #38bdf8;
    }
    .step.s-base.active {
      box-shadow: 0 0 0 3px #1e2945;
      background: #0284c7;
      color: #fff;
    }

    .prefix {
      font-size: 13px;
      font-weight: 700;
      line-height: 1.1;
      text-align: center;
    }
    .symbol {
      font-size: 11px;
      opacity: 0.75;
      margin-top: 2px;
    }
    .val {
      font-size: 11px;
      font-weight: 600;
      margin-top: auto;
      text-align: center;
      line-height: 1;
      padding-bottom: 2px;
    }

    /* Interactive Jump Banner / Readout */
    .readout {
      width: 100%;
      max-width: 580px;
      background: #fff;
      border: 1px solid #cbd5e1;
      border-radius: 10px;
      padding: 8px 12px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 8px;
      margin-top: 8px;
    }

    .math-display {
      font-size: 15px;
      font-weight: 700;
      color: #1e2945;
      display: flex;
      align-items: center;
      gap: 6px;
      flex-wrap: wrap;
    }
    .math-badge {
      background: #e0f2fe;
      color: #0369a1;
      padding: 2px 8px;
      border-radius: 6px;
      font-size: 14px;
    }

    .btn-group {
      display: flex;
      gap: 6px;
    }
    .btn {
      background: #1e2945;
      color: #fff;
      border: none;
      border-radius: 6px;
      padding: 6px 10px;
      font-size: 13px;
      font-weight: 600;
      cursor: pointer;
    }
    .btn:active { opacity: 0.8; }
    .btn-subtle {
      background: #f1f5f9;
      color: #475569;
      border: 1px solid #cbd5e1;
    }

    @media (max-width: 420px) {
      .prefix { font-size: 11px; }
      .symbol { font-size: 10px; }
      .val { font-size: 10px; }
      .dir-banner { font-size: 11px; padding: 2px 6px; }
      .math-display { font-size: 13px; }
    }
  </style>
</head>
<body>

  
  <div class="header-nav">
    <div class="dir-banner left">
      <span>← ÷10</span>
    </div>
    <div class="dir-banner right">
      <span>×10 →</span>
    </div>
  </div>

  
  <div class="ladder" id="ladder">
    <div class="step s-kilo" data-idx="0" data-mult="1000" data-name="kilo" data-unit="km">
      <span class="prefix">kilo</span>
      <span class="symbol">k</span>
      <span class="val">1,000</span>
    </div>
    <div class="step s-hecto" data-idx="1" data-mult="100" data-name="hecto" data-unit="hm">
      <span class="prefix">hecto</span>
      <span class="symbol">h</span>
      <span class="val">100</span>
    </div>
    <div class="step s-deka" data-idx="2" data-mult="10" data-name="deka" data-unit="dam">
      <span class="prefix">deka</span>
      <span class="symbol">da</span>
      <span class="val">10</span>
    </div>
    <div class="step s-base active" data-idx="3" data-mult="1" data-name="Base" data-unit="m">
      <span class="prefix">Base</span>
      <span class="symbol">m, g, L</span>
      <span class="val">1</span>
    </div>
    <div class="step s-deci" data-idx="4" data-mult="0.1" data-name="deci" data-unit="dm">
      <span class="prefix">deci</span>
      <span class="symbol">d</span>
      <span class="val">0.1</span>
    </div>
    <div class="step s-centi" data-idx="5" data-mult="0.01" data-name="centi" data-unit="cm">
      <span class="prefix">centi</span>
      <span class="symbol">c</span>
      <span class="val">0.01</span>
    </div>
    <div class="step s-milli" data-idx="6" data-mult="0.001" data-name="milli" data-unit="mm">
      <span class="prefix">milli</span>
      <span class="symbol">m</span>
      <span class="val">0.001</span>
    </div>
  </div>

  
  <div class="readout">
    <div class="math-display" id="readoutText">
      <span>1 km</span>
      <span>=</span>
      <span class="math-badge">1,000 m</span>
    </div>
    <div class="btn-group">
      <button class="btn btn-subtle" id="prevBtn" aria-label="Step Left">←</button>
      <button class="btn" id="playBtn">5 km → m</button>
      <button class="btn btn-subtle" id="nextBtn" aria-label="Step Right">→</button>
    </div>
  </div>

  <script>
    const steps = document.querySelectorAll('.step');
    const readoutText = document.getElementById('readoutText');
    const playBtn = document.getElementById('playBtn');
    const prevBtn = document.getElementById('prevBtn');
    const nextBtn = document.getElementById('nextBtn');

    let currentIdx = 0; // kilo

    function updateStep(idx) {
      currentIdx = Math.max(0, Math.min(steps.length - 1, idx));
      steps.forEach((s, i) => {
        s.classList.toggle('active', i === currentIdx);
      });

      const current = steps[currentIdx];
      const mult = parseFloat(current.dataset.mult);
      const name = current.dataset.name;
      const unit = current.dataset.unit;

      if (mult >= 1) {
        readoutText.innerHTML = `<span>1 ${unit}</span> = <span class="math-badge">${mult.toLocaleString()} m</span>`;
      } else {
        const inv = Math.round(1 / mult);
        readoutText.innerHTML = `<span>1 m</span> = <span class="math-badge">${inv.toLocaleString()} ${unit}</span>`;
      }
    }

    steps.forEach((s, i) => {
      s.addEventListener('click', () => updateStep(i));
    });

    prevBtn.addEventListener('click', () => updateStep(currentIdx - 1));
    nextBtn.addEventListener('click', () => updateStep(currentIdx + 1));

    let exampleState = false;
    playBtn.addEventListener('click', () => {
      exampleState = !exampleState;
      if (exampleState) {
        updateStep(0);
        readoutText.innerHTML = `<span>5 km</span> <span>× 1,000</span> = <span class="math-badge">5,000 m</span>`;
        playBtn.textContent = 'Reset';
      } else {
        updateStep(3);
        playBtn.textContent = '5 km → m';
      }
    });

    // Initialize at kilo to set up context for km -> m
    updateStep(0);
  </script>
</body>
</html>

Understanding Metric Prefixes and Place Value in Length

Converting Millimetres to Centimetres with Decimals

Converting Centimetres to Millimetres with Decimals

Converting Centimetres to Metres with Two Decimal Places

Converting Metres to Centimetres with Decimals

Converting Millimetres to Metres with Three Decimal Places

Converting Metres to Millimetres with Decimals

Converting Metres to Kilometres with Three Decimal Places

Converting Kilometres to Metres with Decimals

Comparing and Ordering Mixed Metric Lengths

Solving Length Conversion Word Problems

math

Converting Metric Units of Length

Understanding Metric Mass Units and Decimal Notation

Converting Grams to Kilograms with Three Decimal Places

Converting Kilograms to Grams with Decimals

Converting Kilograms to Tonnes and Tonnes to Kilograms

Understanding Metric Capacity Units and Decimal Notation

Converting Millilitres to Litres with Three Decimal Places

Converting Litres to Millilitres with Decimals

Converting Between Centilitres, Millilitres and Litres

Comparing and Ordering Mass and Capacity Measurements

Solving Mass and Capacity Conversion Word Problems

Converting Metric Mass and Capacity

认识土地面积单位：公顷

认识平方千米与面积单位换算

平行四边形面积公式的割补推导

平行四边形面积计算中的底高对应

三角形面积公式的倍拼推导

三角形面积应用与等底等高模型

梯形面积公式的转化推导与计算

梯形面积的实际应用与钢管堆放问题

组合图形面积计算：分割法与添补法

估算不规则图形面积：数方格与近似图形法

平面多边形面积与大面积单位测量

Converting Seconds to Minutes and Minutes to Seconds

Converting Minutes to Hours and Hours to Minutes

Expressing Time Remainders as Fractions and Decimals

Converting Between Hours, Days, Weeks and Months

Converting Between 12-Hour and 24-Hour Clock Times

Reading and Interpreting Timetables and Schedules

Calculating Time Intervals Across Midnight and Days

Solving Multi-Step Word Problems Involving Time Conversions

Converting Units of Time and Calculating Durations

Concepto de número racional y representación fraccionaria

Fracciones propias, impropias y números mixtos

Fracciones equivalentes por amplificación y simplificación

Fracción irreducible y simplificación máxima

Ubicación de fracciones positivas y negativas en la recta

Comparación de fracciones con distinto denominador

Densidad de los números racionales

Fracciones como operadores de cantidades y medidas

Problemas de comparación y medición con fracciones

Números racionales: Fracciones y equivalencia

Understanding Imperial and Metric Units of Distance

The 5 Miles to 8 Kilometres Relationship

Converting Miles to Kilometres Using Multiplication and Division

Converting Kilometres to Miles Using Multiplication and Division

Converting Between Miles and Kilometres with Decimals

Reading and Interpreting Miles to Kilometres Conversion Graphs

Drawing Conversion Graphs Between Miles and Kilometres

Comparing Speed Limits and Distances in Miles and Kilometres

Solving Real-World Travel Word Problems with Miles and Kilometres

Converting Between Miles and Kilometres

长方体和正方体的特征：面、棱、顶点

正方体与长方体的表面展开图识别

长方体和正方体表面积公式推导与计算

表面积的实际应用：粉刷教室与无盖容器

体积与容积的意义及度量单位（m³、dm³、cm³、L、mL）

体积与容积单位之间的进率与换算

长方体和正方体体积公式推导与计算（V=abh, V=a³, V=Sh）

切割与拼截问题中的表面积与体积变化规律

排水法测量不规则物体的体积

长方体和正方体的特征、表面积与体积

Concepto de inverso multiplicativo o recíproco

División de fracciones por el método del recíproco

División con fracciones y números mixtos

Operaciones combinadas con fracciones y jerarquía

Problemas verbales aditivos con fracciones en medidas

Problemas verbales multiplicativos y de división con fracciones

División, operaciones combinadas y problemas con fracciones

Solving Addition and Subtraction Problems with Three Decimal Places

Multiplying Decimal Measurements by Whole Numbers

Dividing Decimal Measurements by Whole Numbers

Converting Units Before Calculating in Multi-Step Problems

Solving Measurement Word Problems with Up to Three Decimal Places

Solving Money and Pricing Problems Per Unit Measure

Estimating and Rounding Answers in Measurement Problems

Solving Two-Step and Three-Step Measurement Word Problems

Solving Decimal Measurement Word Problems

Deriving the Area of a Right-Angled Triangle from a Rectangle

Calculating the Area of Right-Angled Triangles

Identifying the Perpendicular Height of Any Triangle

Deriving the General Formula for the Area of a Triangle

Calculating the Area of Acute and Obtuse Triangles

Deriving the Formula for the Area of a Parallelogram

Identifying the Base and Perpendicular Height of a Parallelogram

Calculating the Area of Parallelograms

Finding Missing Dimensions of Triangles and Parallelograms

Solving Word Problems Involving Triangle and Parallelogram Areas

Calculating the Area of Triangles and Parallelograms

Splitting Compound Shapes into Rectangles and Triangles

Calculating the Area of L-Shaped and T-Shaped Polygons

Calculating the Area of Composite Shapes with Triangles and Parallelograms

Calculating Shaded and Subtractive Areas

Writing and Using Algebraic Formulae for 2D Areas

Deriving the Area of a Trapezium by Decomposition

Solving Complex Area Word Problems with Mixed Units

Estimating Areas of Irregular 2D Shapes on Grids

Area of Compound Shapes and Algebraic Formulae

Converting Customary Units Using Ratio Reasoning

Introduction to Dimensional Analysis and Unit Cancellation

Converting Between Metric and Customary Systems

Converting Compound Units and Speeds

Converting Units of Area and Volume

Solving Multi-Step Measurement Conversion Word Problems

Dimensional Analysis and Measurement Conversions

Connecting Volume in Cubic Centimetres to Liquid Capacity in Millilitres

Estimating the Volume of Everyday 3D Objects

Comparing Volumes of Cuboids with Different Dimensions

Finding Missing Dimensions of Cubes and Cuboids

Calculating the Volume of Composite 3D Shapes

Solving Word Problems Involving Volume and Capacity

Applying Volume: Capacity, Composite Shapes, and Problem Solving

Concepto de razón y formas de representación

Razones equivalentes y tablas de razón

Concepto de tasa y tasa unitaria

Comparación de precios unitarios para la mejor compra

Concepto de proporcionalidad directa y constante k

Ecuaciones de proporcionalidad directa: y = kx

Gráficas de proporcionalidad directa en el plano

Regla de tres simple directa

Problemas de velocidad constante, distancia y tiempo

Factores de conversión unitarios con proporcionalidad

Razones, tasas y proporcionalidad directa

Converting Between Measurement Systems

Multi-Step Measurement Conversion Problems

Measurement Conversion Using Ratio Reasoning

Understanding Metric Units of Length

Converting Between Metric Units of Length

Understanding Metric Units of Mass

Converting Between Metric Units of Mass

Understanding Metric Units of Capacity

Converting Between Metric Units of Capacity

Decimal Representations in Measurement

Choosing Appropriate Units of Measurement

Metric Units of Measurement

Using Tape Diagrams to Solve Ratio Problems

Using Double Number Lines to Solve Ratio Problems

Mixed Ratio Reasoning Word Problems

Ratio and Rate Problem-Solving Assessment

Visual Strategies for Ratio Problem Solving

Understanding Unit Conversion Within Measurement Systems

Converting Customary Length Units

Converting Customary Weight Units

Converting Customary Capacity Units

Converting Metric Length Units

Converting Metric Mass Units

Converting Metric Capacity Units

Converting Time Units

Converting Units in Measurement Systems

Perímetro de polígonos regulares e irregulares

Área de rectángulos, paralelogramos y cuadrados

Área de triángulos y su justificación geométrica

Área de trapecios y rombos

Área de polígonos regulares: apotema y perímetro

Elementos del círculo y la circunferencia

El número pi y la longitud de la circunferencia

Área del círculo y justificación por sectores

Área de figuras compuestas por adición y sustracción

Resolución de problemas reales de áreas y costos de materiales

Perímetro, área y geometría del círculo

Using Proportions for Unit Conversions

Using Unit Rates for Conversions

Rational Numbers in Daily Life: Length, Weight, and Capacity

Generalizing and Applying Measurement Conversions

Sistema Internacional de Unidades y prefijos métricos

Conversión de unidades de longitud y distancia

Conversión de unidades de superficie y área

Conversión de unidades de volumen y capacidad

Conversión de unidades de masa y peso

Unidades de tiempo y cálculo de intervalos

Técnicas de estimación de longitudes y distancias

Estimación de áreas irregulares mediante cuadrículas

Estimación de masas, capacidades y cantidades discontinuas

Análisis de variaciones en las medidas y margen de error

Magnitudes, unidades de medida y estimación

Volume of Rectangular Prisms with Fractional Edge Lengths

Volume of Rectangular Prisms with Decimal Edge Lengths

Surface Area of Rectangular Prisms

Surface Area of Triangular Prisms

Surface Area of Pyramids

Using Nets to Find Surface Area

Solving Real-World Perimeter, Area and Volume Problems

Relating Perimeter, Area, and Volume

Justifying Geometric Solutions with Precise Language

Geometry: Volume, Surface Area, and Real-World Applications

OGM.7.RP.6

Aligned learning resources

Related diagrams