<!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>Place Value: 23</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      width: 100%;
      min-height: 100%;
      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;
      padding: 12px;
      user-select: none;
    }

    .pv-chart {
      width: 100%;
      max-width: 480px;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .columns-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 12px;
    }

    .pv-col {
      display: flex;
      flex-direction: column;
      align-items: center;
      border-radius: 14px;
      padding: 12px 8px;
    }

    .tens-col {
      background: #eff6ff;
      border: 2px solid #bfdbfe;
    }

    .ones-col {
      background: #fff7ed;
      border: 2px solid #fed7aa;
    }

    .col-header {
      font-size: 22px;
      font-weight: 800;
      letter-spacing: 0.5px;
      margin-bottom: 12px;
    }

    .tens-header {
      color: #2563eb;
    }

    .ones-header {
      color: #ea580c;
    }

    .blocks-zone {
      height: 170px;
      width: 100%;
      display: flex;
      align-items: flex-end;
      justify-content: center;
      gap: 12px;
      padding-bottom: 4px;
    }

    /* 10-Rod */
    .ten-rod {
      width: 18px;
      height: 160px;
      display: flex;
      flex-direction: column;
      border-radius: 4px;
      overflow: hidden;
      box-shadow: 0 2px 4px rgba(37, 99, 235, 0.2);
      border: 1.5px solid #1d4ed8;
    }

    .rod-segment {
      width: 100%;
      height: 16px;
      background: #3b82f6;
      border-bottom: 1px solid #1d4ed8;
    }

    .rod-segment:last-child {
      border-bottom: none;
    }

    /* Unit Cubes */
    .unit-cubes {
      display: flex;
      gap: 8px;
      align-items: flex-end;
      padding-bottom: 2px;
    }

    .unit-cube {
      width: 18px;
      height: 18px;
      background: #f97316;
      border: 1.5px solid #c2410c;
      border-radius: 3px;
      box-shadow: 0 2px 4px rgba(234, 88, 12, 0.2);
    }

    .digits-box {
      margin-top: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 2px;
    }

    .digit-main {
      font-size: 32px;
      font-weight: 900;
      line-height: 1;
    }

    .digit-tens {
      color: #1d4ed8;
    }

    .digit-ones {
      color: #c2410c;
    }

    .digit-value {
      font-size: 13px;
      font-weight: 700;
      border-radius: 6px;
      padding: 2px 8px;
    }

    .value-tens {
      background: #dbeafe;
      color: #1e40af;
    }

    .value-ones {
      background: #ffedd5;
      color: #9a3412;
    }

    /* Bottom Summary Bar */
    .equation-bar {
      background: #f8fafc;
      border: 2px solid #e2e8f0;
      border-radius: 12px;
      padding: 10px 14px;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      font-size: 18px;
      font-weight: 800;
      flex-wrap: wrap;
    }

    .eq-tens {
      color: #2563eb;
    }

    .eq-ones {
      color: #ea580c;
    }

    .eq-total {
      color: #0f172a;
      background: #e2e8f0;
      padding: 2px 10px;
      border-radius: 6px;
      margin-left: 2px;
    }
  </style>
</head>
<body>

  <div class="pv-chart">
    <div class="columns-row">
      
      <div class="pv-col tens-col">
        <div class="col-header tens-header">Tens</div>
        
        <div class="blocks-zone">
          <div class="ten-rod">
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
          </div>
          <div class="ten-rod">
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
          </div>
        </div>

        <div class="digits-box">
          <div class="digit-main digit-tens">2</div>
          <div class="digit-value value-tens">20</div>
        </div>
      </div>

      
      <div class="pv-col ones-col">
        <div class="col-header ones-header">Ones</div>
        
        <div class="blocks-zone">
          <div class="unit-cubes">
            <div class="unit-cube"></div>
            <div class="unit-cube"></div>
            <div class="unit-cube"></div>
          </div>
        </div>

        <div class="digits-box">
          <div class="digit-main digit-ones">3</div>
          <div class="digit-value value-ones">3</div>
        </div>
      </div>
    </div>

    
    <div class="equation-bar">
      <span class="eq-tens">2 Tens</span>
      <span>+</span>
      <span class="eq-ones">3 Ones</span>
      <span>=</span>
      <span class="eq-total">23</span>
    </div>
  </div>

</body>
</html>

Understanding Tens and Ones in Two-Digit Numbers

<!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;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    }

    body {
      width: 100%;
      min-height: 100%;
      background: #ffffff;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      padding: 12px;
    }

    .comparison-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 12px;
      width: 100%;
      max-width: 480px;
    }

    .num-card {
      background: #f8fafc;
      border: 2px solid #e2e8f0;
      border-radius: 14px;
      padding: 12px 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      position: relative;
      transition: border-color 0.25s ease, box-shadow 0.25s ease;
    }

    .num-card.winner {
      border-color: #0284c7;
      background: #f0f9ff;
    }

    .big-num {
      font-size: 38px;
      font-weight: 800;
      line-height: 1;
      margin-bottom: 4px;
      letter-spacing: -1px;
    }

    .digit-tens {
      color: #0284c7;
    }

    .digit-ones {
      color: #ea580c;
    }

    .label {
      font-size: 13px;
      font-weight: 700;
      color: #64748b;
      margin-bottom: 12px;
    }

    .blocks-area {
      display: flex;
      align-items: flex-end;
      justify-content: center;
      gap: 10px;
      min-height: 135px;
      padding: 6px 0;
    }

    .rods-group, .units-group {
      display: flex;
      align-items: flex-end;
      gap: 4px;
    }

    .units-group {
      flex-direction: column-reverse;
      gap: 3px;
      margin-bottom: 2px;
    }

    /* Ten Rod (SVG rendered) */
    .ten-rod {
      width: 15px;
      height: 120px;
    }

    /* Unit Cube (SVG rendered) */
    .unit-cube {
      width: 15px;
      height: 11px;
    }

    .sub-count {
      margin-top: 10px;
      font-size: 13px;
      font-weight: 700;
      display: flex;
      gap: 6px;
    }

    .tens-pill {
      background: #e0f2fe;
      color: #0369a1;
      padding: 2px 7px;
      border-radius: 6px;
    }

    .ones-pill {
      background: #ffedd5;
      color: #c2410c;
      padding: 2px 7px;
      border-radius: 6px;
    }

    .compare-badge {
      margin-top: 12px;
      width: 100%;
      max-width: 480px;
      background: #0284c7;
      color: #ffffff;
      padding: 8px 14px;
      border-radius: 10px;
      text-align: center;
      font-size: 14px;
      font-weight: 700;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
    }

    .symbol {
      font-size: 16px;
      color: #fde047;
    }
  </style>
</head>
<body>

  <div class="comparison-grid">
    
    <div class="num-card">
      <div class="big-num">
        <span class="digit-tens">2</span><span class="digit-ones">3</span>
      </div>
      <div class="label">Total: 23</div>

      <div class="blocks-area">
        
        <div class="rods-group">
          
          <svg class="ten-rod" viewBox="0 0 16 120">
            <rect width="16" height="120" rx="3" fill="#0284c7" />
            <line x1="0" y1="12" x2="16" y2="12" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="24" x2="16" y2="24" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="36" x2="16" y2="36" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="48" x2="16" y2="48" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="60" x2="16" y2="60" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="72" x2="16" y2="72" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="84" x2="16" y2="84" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="96" x2="16" y2="96" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="108" x2="16" y2="108" stroke="#bae6fd" stroke-width="1.2"/>
          </svg>
          
          <svg class="ten-rod" viewBox="0 0 16 120">
            <rect width="16" height="120" rx="3" fill="#0284c7" />
            <line x1="0" y1="12" x2="16" y2="12" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="24" x2="16" y2="24" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="36" x2="16" y2="36" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="48" x2="16" y2="48" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="60" x2="16" y2="60" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="72" x2="16" y2="72" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="84" x2="16" y2="84" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="96" x2="16" y2="96" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="108" x2="16" y2="108" stroke="#bae6fd" stroke-width="1.2"/>
          </svg>
        </div>

        
        <div class="units-group">
          <svg class="unit-cube" viewBox="0 0 16 11">
            <rect width="16" height="11" rx="2" fill="#ea580c" stroke="#fed7aa" stroke-width="1"/>
          </svg>
          <svg class="unit-cube" viewBox="0 0 16 11">
            <rect width="16" height="11" rx="2" fill="#ea580c" stroke="#fed7aa" stroke-width="1"/>
          </svg>
          <svg class="unit-cube" viewBox="0 0 16 11">
            <rect width="16" height="11" rx="2" fill="#ea580c" stroke="#fed7aa" stroke-width="1"/>
          </svg>
        </div>
      </div>

      <div class="sub-count">
        <span class="tens-pill">2 Tens</span>
        <span class="ones-pill">3 Ones</span>
      </div>
    </div>

    
    <div class="num-card winner">
      <div class="big-num">
        <span class="digit-tens">3</span><span class="digit-ones">2</span>
      </div>
      <div class="label">Total: 32</div>

      <div class="blocks-area">
        
        <div class="rods-group">
          
          <svg class="ten-rod" viewBox="0 0 16 120">
            <rect width="16" height="120" rx="3" fill="#0284c7" />
            <line x1="0" y1="12" x2="16" y2="12" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="24" x2="16" y2="24" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="36" x2="16" y2="36" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="48" x2="16" y2="48" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="60" x2="16" y2="60" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="72" x2="16" y2="72" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="84" x2="16" y2="84" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="96" x2="16" y2="96" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="108" x2="16" y2="108" stroke="#bae6fd" stroke-width="1.2"/>
          </svg>
          
          <svg class="ten-rod" viewBox="0 0 16 120">
            <rect width="16" height="120" rx="3" fill="#0284c7" />
            <line x1="0" y1="12" x2="16" y2="12" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="24" x2="16" y2="24" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="36" x2="16" y2="36" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="48" x2="16" y2="48" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="60" x2="16" y2="60" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="72" x2="16" y2="72" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="84" x2="16" y2="84" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="96" x2="16" y2="96" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="108" x2="16" y2="108" stroke="#bae6fd" stroke-width="1.2"/>
          </svg>
          
          <svg class="ten-rod" viewBox="0 0 16 120">
            <rect width="16" height="120" rx="3" fill="#0284c7" />
            <line x1="0" y1="12" x2="16" y2="12" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="24" x2="16" y2="24" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="36" x2="16" y2="36" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="48" x2="16" y2="48" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="60" x2="16" y2="60" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="72" x2="16" y2="72" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="84" x2="16" y2="84" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="96" x2="16" y2="96" stroke="#bae6fd" stroke-width="1.2"/>
            <line x1="0" y1="108" x2="16" y2="108" stroke="#bae6fd" stroke-width="1.2"/>
          </svg>
        </div>

        
        <div class="units-group">
          <svg class="unit-cube" viewBox="0 0 16 11">
            <rect width="16" height="11" rx="2" fill="#ea580c" stroke="#fed7aa" stroke-width="1"/>
          </svg>
          <svg class="unit-cube" viewBox="0 0 16 11">
            <rect width="16" height="11" rx="2" fill="#ea580c" stroke="#fed7aa" stroke-width="1"/>
          </svg>
        </div>
      </div>

      <div class="sub-count">
        <span class="tens-pill">3 Tens</span>
        <span class="ones-pill">2 Ones</span>
      </div>
    </div>
  </div>

  
  <div class="compare-badge">
    <span>32 is bigger: <strong>3 Tens &gt; 2 Tens</strong></span>
  </div>

</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">
  <title>Tens and Ones Diagram</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      user-select: none;
    }

    body {
      width: 100%;
      min-height: 100%;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      padding: 12px;
      background: #ffffff;
      color: #1e2945;
    }

    .main-grid {
      width: 100%;
      max-width: 480px;
      display: flex;
      flex-direction: column;
      gap: 12px;
      align-items: center;
    }

    .blocks-container {
      width: 100%;
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 12px;
    }

    .place-zone {
      background: #f8fafc;
      border-radius: 12px;
      padding: 10px 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 8px;
      min-height: 170px;
    }

    .place-zone.tens-zone {
      background: #eff6ff;
      border: 2px solid #bfdbfe;
    }

    .place-zone.ones-zone {
      background: #fff7ed;
      border: 2px solid #fed7aa;
    }

    .zone-title {
      font-size: 14px;
      font-weight: 700;
      letter-spacing: 0.5px;
      text-transform: uppercase;
    }

    .tens-title { color: #1d4ed8; }
    .ones-title { color: #c2410c; }

    .blocks-display {
      flex: 1;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      width: 100%;
    }

    /* 10-rod */
    .ten-rod {
      width: 16px;
      height: 130px;
      background: #2563eb;
      border-radius: 4px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      padding: 1px 0;
      box-shadow: 0 2px 4px rgba(37, 99, 235, 0.25);
    }

    .rod-segment {
      height: 11px;
      margin: 0 1px;
      background: #60a5fa;
      border-radius: 1px;
      border-bottom: 1px solid #1d4ed8;
    }

    .rod-segment:last-child {
      border-bottom: none;
    }

    /* 1-cube */
    .unit-cubes-grid {
      display: flex;
      flex-wrap: wrap;
      width: 72px;
      gap: 6px;
      justify-content: center;
      align-content: center;
    }

    .unit-cube {
      width: 18px;
      height: 18px;
      background: #ea580c;
      border-radius: 4px;
      border: 2px solid #fed7aa;
      box-shadow: 0 2px 4px rgba(234, 88, 12, 0.25);
    }

    .digits-row {
      width: 100%;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
    }

    .digit-card {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      padding: 6px 12px;
      border-radius: 8px;
      font-size: 15px;
      font-weight: 700;
    }

    .digit-tens {
      background: #dbeafe;
      color: #1e40af;
      border: 1px solid #93c5fd;
    }

    .digit-ones {
      background: #ffedd5;
      color: #9a3412;
      border: 1px solid #fdba74;
    }

    .digit-arrow {
      font-size: 18px;
      font-weight: 900;
      color: #64748b;
    }

    .digit-result {
      background: #f1f5f9;
      color: #0f172a;
      border: 2px solid #cbd5e1;
      font-size: 18px;
      padding: 6px 14px;
    }

    .action-btn {
      appearance: none;
      border: none;
      outline: none;
      background: #2563eb;
      color: #ffffff;
      font-size: 14px;
      font-weight: 700;
      padding: 10px 20px;
      border-radius: 20px;
      cursor: pointer;
      box-shadow: 0 3px 8px rgba(37, 99, 235, 0.3);
      transition: background 0.2s ease, box-shadow 0.2s ease;
    }

    .action-btn:hover {
      background: #1d4ed8;
      box-shadow: 0 4px 12px rgba(29, 78, 216, 0.4);
    }

    .action-btn:active {
      background: #1e40af;
    }

    .expanded-card {
      width: 100%;
      height: 46px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 20px;
      font-weight: 800;
      background: #f8fafc;
      border: 2px dashed #cbd5e1;
      border-radius: 10px;
      color: #334155;
      transition: all 0.3s ease;
    }

    .expanded-card.active {
      background: #ecfdf5;
      border: 2px solid #6ee7b7;
      color: #065f46;
    }

    .val-tens { color: #2563eb; }
    .val-plus { color: #64748b; margin: 0 6px; }
    .val-ones { color: #ea580c; }
    .val-eq { color: #64748b; margin: 0 6px; }
    .val-total { color: #059669; }
  </style>
</head>
<body>
  <div class="main-grid">
    <div class="blocks-container">
      
      <div class="place-zone tens-zone">
        <span class="zone-title tens-title">Tens</span>
        <div class="blocks-display">
          <div class="ten-rod">
            <div class="rod-segment"></div><div class="rod-segment"></div>
            <div class="rod-segment"></div><div class="rod-segment"></div>
            <div class="rod-segment"></div><div class="rod-segment"></div>
            <div class="rod-segment"></div><div class="rod-segment"></div>
            <div class="rod-segment"></div><div class="rod-segment"></div>
          </div>
          <div class="ten-rod">
            <div class="rod-segment"></div><div class="rod-segment"></div>
            <div class="rod-segment"></div><div class="rod-segment"></div>
            <div class="rod-segment"></div><div class="rod-segment"></div>
            <div class="rod-segment"></div><div class="rod-segment"></div>
            <div class="rod-segment"></div><div class="rod-segment"></div>
          </div>
          <div class="ten-rod">
            <div class="rod-segment"></div><div class="rod-segment"></div>
            <div class="rod-segment"></div><div class="rod-segment"></div>
            <div class="rod-segment"></div><div class="rod-segment"></div>
            <div class="rod-segment"></div><div class="rod-segment"></div>
            <div class="rod-segment"></div><div class="rod-segment"></div>
          </div>
          <div class="ten-rod">
            <div class="rod-segment"></div><div class="rod-segment"></div>
            <div class="rod-segment"></div><div class="rod-segment"></div>
            <div class="rod-segment"></div><div class="rod-segment"></div>
            <div class="rod-segment"></div><div class="rod-segment"></div>
            <div class="rod-segment"></div><div class="rod-segment"></div>
          </div>
        </div>
      </div>

      
      <div class="place-zone ones-zone">
        <span class="zone-title ones-title">Ones</span>
        <div class="blocks-display">
          <div class="unit-cubes-grid">
            <div class="unit-cube"></div>
            <div class="unit-cube"></div>
            <div class="unit-cube"></div>
            <div class="unit-cube"></div>
            <div class="unit-cube"></div>
          </div>
        </div>
      </div>
    </div>

    
    <div class="digits-row">
      <div class="digit-card digit-tens">Tens: 4</div>
      <div class="digit-card digit-ones">Ones: 5</div>
      <span class="digit-arrow">→</span>
      <div class="digit-card digit-result">45</div>
    </div>

    
    <div class="expanded-card" id="totalBox">
      <span>?</span>
    </div>

    <button class="action-btn" id="toggleBtn" onclick="toggleTotal()">Show Total</button>
  </div>

  <script>
    let visible = false;
    const box = document.getElementById('totalBox');
    const btn = document.getElementById('toggleBtn');

    function toggleTotal() {
      visible = !visible;
      if (visible) {
        box.innerHTML = '<span class="val-tens">40</span><span class="val-plus">+</span><span class="val-ones">5</span><span class="val-eq">=</span><span class="val-total">45</span>';
        box.classList.add('active');
        btn.textContent = 'Hide Total';
      } else {
        box.innerHTML = '<span>?</span>';
        box.classList.remove('active');
        btn.textContent = 'Show Total';
      }
    }
  </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;
      -webkit-tap-highlight-color: transparent;
    }

    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: #f8fafc;
      color: #1e293b;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
      padding: 12px;
      user-select: none;
    }

    .main-stage {
      width: 100%;
      max-width: 580px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 14px;
    }

    .panels-row {
      width: 100%;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 8px;
    }

    .panel-card {
      flex: 1;
      background: #ffffff;
      border-radius: 16px;
      border: 2px solid #e2e8f0;
      padding: 14px 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 250px;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.04);
      position: relative;
    }

    .panel-card.active {
      border-color: #3b82f6;
      box-shadow: 0 6px 16px rgba(59, 130, 246, 0.15);
    }

    .panel-title {
      font-size: 17px;
      font-weight: 800;
      color: #0f172a;
      letter-spacing: -0.01em;
    }

    .ones-title { color: #d97706; }
    .ten-title { color: #2563eb; }

    /* Visual display boxes */
    .cubes-display {
      flex: 1;
      display: flex;
      align-items: center;
      justify-content: center;
      width: 100%;
      position: relative;
    }

    /* 10 loose ones grid */
    .ones-grid {
      display: grid;
      grid-template-columns: repeat(2, 24px);
      grid-template-rows: repeat(5, 24px);
      gap: 8px;
      justify-content: center;
    }

    .unit-cube {
      width: 24px;
      height: 24px;
      background: linear-gradient(135deg, #fef08a, #f59e0b);
      border: 1.5px solid #d97706;
      border-radius: 4px;
      box-shadow: inset 1px 1px 0 rgba(255, 255, 255, 0.6), 0 2px 4px rgba(217, 119, 6, 0.25);
      transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.3s ease;
    }

    /* 1 Ten Rod (10 connected segments) */
    .ten-rod {
      width: 24px;
      height: 160px;
      display: flex;
      flex-direction: column;
      border: 1.5px solid #1d4ed8;
      border-radius: 4px;
      overflow: hidden;
      box-shadow: 0 4px 10px rgba(37, 99, 235, 0.25);
      background: #3b82f6;
    }

    .rod-segment {
      width: 100%;
      height: 16px;
      background: linear-gradient(135deg, #93c5fd, #2563eb);
      border-bottom: 1px solid rgba(29, 78, 216, 0.6);
      box-shadow: inset 1px 1px 0 rgba(255, 255, 255, 0.4);
      transition: background 0.3s ease;
    }

    .rod-segment:last-child {
      border-bottom: none;
    }

    /* Middle Connector & Controls */
    .action-col {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 8px;
      min-width: 90px;
    }

    .arrow-icon {
      font-size: 24px;
      color: #94a3b8;
      transition: color 0.3s ease, transform 0.3s ease;
    }

    .arrow-icon.active {
      color: #3b82f6;
      transform: translateX(3px);
    }

    .action-btn {
      appearance: none;
      border: none;
      background: #2563eb;
      color: #ffffff;
      font-size: 13px;
      font-weight: 700;
      padding: 9px 12px;
      border-radius: 20px;
      cursor: pointer;
      box-shadow: 0 3px 8px rgba(37, 99, 235, 0.3);
      display: flex;
      align-items: center;
      gap: 4px;
      transition: background 0.2s ease, box-shadow 0.2s ease;
    }

    .action-btn:active {
      background: #1d4ed8;
      box-shadow: 0 1px 4px rgba(37, 99, 235, 0.4);
    }

    /* Bottom Equality Banner */
    .equality-bar {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 10px;
      background: #ffffff;
      border: 2px solid #e2e8f0;
      border-radius: 30px;
      padding: 6px 18px;
      font-size: 15px;
      font-weight: 800;
      color: #334155;
    }

    .eq-ones { color: #d97706; }
    .eq-sign { color: #64748b; font-size: 18px; }
    .eq-ten { color: #2563eb; }

    /* Animated states */
    .glow-rod {
      animation: rodPulse 1.2s infinite alternate ease-in-out;
    }

    @keyframes rodPulse {
      0% { box-shadow: 0 0 4px #60a5fa; }
      100% { box-shadow: 0 0 16px #2563eb, 0 0 24px #93c5fd; }
    }

    @media (max-width: 400px) {
      .panel-title { font-size: 15px; }
      .action-btn { font-size: 12px; padding: 7px 10px; }
      .action-col { min-width: 76px; }
      .ones-grid { gap: 6px; }
      .unit-cube { width: 22px; height: 22px; }
      .ten-rod { width: 22px; height: 150px; }
      .rod-segment { height: 15px; }
      .equality-bar { font-size: 14px; padding: 5px 14px; }
    }
  </style>
</head>
<body>
  <div class="main-stage">
    <div class="panels-row">
      
      <div class="panel-card" id="leftCard">
        <span class="panel-title ones-title">10 Ones</span>
        <div class="cubes-display">
          <div class="ones-grid" id="onesGrid">
            <div class="unit-cube"></div>
            <div class="unit-cube"></div>
            <div class="unit-cube"></div>
            <div class="unit-cube"></div>
            <div class="unit-cube"></div>
            <div class="unit-cube"></div>
            <div class="unit-cube"></div>
            <div class="unit-cube"></div>
            <div class="unit-cube"></div>
            <div class="unit-cube"></div>
          </div>
        </div>
      </div>

      
      <div class="action-col">
        <div class="arrow-icon" id="arrowIcon">➔</div>
        <button class="action-btn" id="groupBtn" aria-label="Group into 10">Group ➔</button>
      </div>

      
      <div class="panel-card" id="rightCard">
        <span class="panel-title ten-title">1 Ten</span>
        <div class="cubes-display">
          <div class="ten-rod" id="tenRod">
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
            <div class="rod-segment"></div>
          </div>
        </div>
      </div>
    </div>

    
    <div class="equality-bar">
      <span class="eq-ones">10 Ones</span>
      <span class="eq-sign">=</span>
      <span class="eq-ten">1 Ten</span>
    </div>
  </div>

  <script>
    const groupBtn = document.getElementById('groupBtn');
    const onesCubes = document.querySelectorAll('.unit-cube');
    const rodSegments = document.querySelectorAll('.rod-segment');
    const tenRod = document.getElementById('tenRod');
    const arrowIcon = document.getElementById('arrowIcon');
    const leftCard = document.getElementById('leftCard');
    const rightCard = document.getElementById('rightCard');

    let isGrouped = false;

    function playTone(freq, dur = 0.15) {
      try {
        const AudioCtx = window.AudioContext || window.webkitAudioContext;
        if (!AudioCtx) return;
        const ctx = new AudioCtx();
        const osc = ctx.createOscillator();
        const gain = ctx.createGain();
        osc.type = 'sine';
        osc.frequency.value = freq;
        osc.connect(gain);
        gain.connect(ctx.destination);
        gain.gain.setValueAtTime(0.2, ctx.currentTime);
        gain.gain.exponentialRampToValueAtTime(0.001, ctx.currentTime + dur);
        osc.start();
        osc.stop(ctx.currentTime + dur);
      } catch (e) {}
    }

    function applyGroupAnimation() {
      if (!isGrouped) {
        // Grouping: cubes light up and step together
        isGrouped = true;
        groupBtn.textContent = 'Reset ↺';
        arrowIcon.classList.add('active');
        leftCard.classList.remove('active');
        rightCard.classList.add('active');
        tenRod.classList.add('glow-rod');

        onesCubes.forEach((cube, i) => {
          setTimeout(() => {
            cube.style.transform = 'scale(0.85)';
            cube.style.opacity = '0.4';
          }, i * 30);
        });

        rodSegments.forEach((seg, i) => {
          setTimeout(() => {
            seg.style.background = 'linear-gradient(135deg, #bfdbfe, #3b82f6)';
            playTone(400 + i * 45, 0.08);
          }, i * 40);
        });
      } else {
        // Reset to original
        isGrouped = false;
        groupBtn.textContent = 'Group ➔';
        arrowIcon.classList.remove('active');
        leftCard.classList.add('active');
        rightCard.classList.remove('active');
        tenRod.classList.remove('glow-rod');

        onesCubes.forEach((cube, i) => {
          cube.style.transform = 'scale(1)';
          cube.style.opacity = '1';
        });

        rodSegments.forEach((seg) => {
          seg.style.background = 'linear-gradient(135deg, #93c5fd, #2563eb)';
        });

        playTone(320, 0.15);
      }
    }

    groupBtn.addEventListener('click', applyGroupAnimation);
    leftCard.classList.add('active');
  </script>
</body>
</html>

Conteo de objetos uno a uno hasta 10

Representación de cantidades con marcas y dibujos hasta 10

Lectura y escritura de números del 0 al 10

El número cero como ausencia de cantidad

Conteo hacia adelante y hacia atrás hasta 20

Conteo de dos en dos hasta 20

Identificación de números pares e impares con parejas

Números ordinales del primero al décimo

math

Conteo, representación y patrones hasta 20

What Is a Set of Objects?

Understanding Zero as an Empty Set

Counting Objects with One-to-One Matching

The Cardinality Principle: The Last Number Tells How Many

Representing Sets with Number Symbols 0 to 10

Representing Sets with Number Symbols 11 to 20

Order Irrelevance in Counting Sets

Subitizing Small Sets Instantly to 5

Conceptual Subitizing Using Ten-Frames

Representing Quantities with Tally Marks

Foundations of Sets and Counting Principles

Counting Groups of Ten and Leftover Ones

Representing Two-Digit Numbers in Different Ways

Identifying Tens and Ones Digits

Understanding Zero as a Placeholder in Tens

Partitioning Two-Digit Numbers into Tens and Ones

Partitioning Two-Digit Numbers in Different Ways

Building Numbers With Different Tens and Ones Combinations

Writing Numbers in Expanded Form to 100

Foundations of Two-Digit Place Value

Understanding Thousands and Ten Thousands

Understanding Hundred Thousands

Introducing Millions Place Value

Reading and Writing Seven-Digit Numbers

Decomposing Large Numbers into Expanded Form

Multiplying and Dividing by 10, 100, and 1000

Reading, Writing, and Representing Large Numbers

Comparing Large Numbers Using Place Value

Ordering Large Numbers from Least to Greatest

Locating Large Numbers on Stepped Number Lines

Finding 1,000, 10,000, and 100,000 More or Less

Solving Place Value Puzzles with Large Numbers

Using Large Numbers in Real-World Contexts

Comparing, Ordering, and Applying Large Numbers

Reading and Writing Number Words to 100

Locating Numbers on a Hundred Chart

Comparing Two-Digit Numbers Using Place Value

Using Comparison Symbols with Two-Digit Numbers

Ordering Sets of Numbers to 100

Locating Two-Digit Numbers on a Number Line

Comparing, Ordering, and Sequencing Numbers to 100

Conteo y agrupación hasta 50 elementos

Conteo de cinco en cinco hasta 50

Conteo de diez en diez hasta 100

Exploración del cuadro numérico del 1 al 100

Identificación del número anterior y posterior hasta 100

Conteo hacia atrás desde 100

Patrones de sumar y restar dos en el tablero de 100

Estimación visual de cantidades hasta 50

Conteo, patrones y sentido numérico hasta 100

Natural Numbers on a Counting Strip

Counting Forward from Any Given Number to 50

Counting Backward from 20 to 0

Identifying One More and One Less in Sets

Comparing Two Sets Using Matching Strategies

Estimating Quantities in Scattered Sets to 20

Solving Real-World Set Counting Problems

Natural Numbers and Sets: Review and Challenge

Number Sequences, Comparing Sets, and Estimation

Understanding Zero as a Placeholder in Tens and Ones

Bundling Ten Tens into One Hundred

Counting Hundreds, Tens and Ones with Base-Ten Blocks

Bundling Ten Hundreds into One Thousand

How Many Tens, Hundreds, and Thousands Are in Whole Numbers

Exploring How Numbers Grow Forever

Place Value and the Base-Ten System

Counting Forward From Any Number Up to 20

Counting Backward From 10 to 0

Counting Backward From 20 to 0

Identifying One More and One Less Up to 20

Comparing Sets Using More, Fewer, and Same

Comparing Numbers Up to 20 Using Greater Than and Less Than

Counting and Comparing Numbers up to 20

Rounding Whole Numbers to the Nearest 10 and 100

Rounding to the Nearest 1,000 and 10,000

Rounding to the Nearest 100,000 and Million

Rounding Decimals to the Nearest Whole Number

Rounding Decimals to One Decimal Place

Estimating Sums and Differences Before Calculating

Estimating Products and Quotients

Using Front-End Estimation and Compatible Numbers

Checking if a Calculated Answer Is Reasonable

Deciding When to Estimate and When to Calculate Exactly

Explaining and Justifying Estimation Methods

Estimation, Rounding, and Reasonableness

Introducing Hundreds and Three-Digit Numbers

Understanding Zero as a Placeholder in Three-Digit Numbers

Showing a Number in Different Ways

Solving Place Value Riddles and Puzzles

Extending Place Value to Three-Digit Numbers

What Is a Ten? Bundling Ones Into Tens

Writing Teen Numbers as Tens and Ones

Counting Tens and Ones With Base-Ten Blocks

Counting Tens and Ones to Find the Total

Which Digit Is Tens and Which Is Ones?

Which Digit Is Tens and Which Is Ones? (51 to 99)

Writing Numbers From Tens and Ones

Matching Numerals to Tens and Ones Representations

Place Value Basics: Understanding Tens and Ones

Construcción de la decena con bloques y unidades

Representación de números del 11 al 19 en decenas y unidades

Lectura y escritura de decenas completas hasta 90

Descomposición aditiva de números de dos cifras

Uso del ábaco para representar números de dos cifras

Valor posicional y decenas hasta 100

Skip Counting by Tens Up to 100

Skip Counting by Fives Up to 50

Skip Counting by Twos Up to 20

Counting Forward Up to 50 on a Hundred Chart

Counting Forward Up to 100 on a Hundred Chart

Understanding That Numbers Keep Going Forever

Counting Past 100 Into the Hundreds

Estimating Quantities in Large Groups

Skip Counting and Exploring Numbers to 100

Construcción de la centena con bloques multibase

Lectura y escritura de centenas completas hasta 900

Representación de números de tres cifras en la tabla de posición

Descomposición expandida de números de tres cifras

Equivalencias entre centenas, decenas y unidades

Valor de un dígito según su posición en el número

Uso del ábaco para números hasta 999

Introducción al número 1.000: la unidad de mil

Cambio y canje de unidades por decenas y centenas

Lectura y escritura de números hasta 1.000

Valor posicional y centenas hasta 1.000

Using Tens and Ones to Build Numbers to 30

Using Tens and Ones to Build Numbers to 50

Decomposing Two-Digit Numbers Into Tens and Ones

Breaking Two-Digit Numbers Into Tens and Ones

Comparing Two-Digit Numbers Using Tens and Ones

Skip-Counting by 10s to 100 with Bundles

What Is a Hundred? Bundling Tens Into Hundreds

Tens and Ones Mastery Synthesis

Working with Two-Digit Numbers: Composing, Decomposing, and Comparing

Comparación de colecciones: más que, menos que e igual que

Símbolos de comparación: mayor que, menor que e igual

Comparación de números de dos cifras usando decenas

Ordenamiento de grupos de números de menor a mayor

Ordenamiento de grupos de números de mayor a menor

Comparación de números de tres cifras

Comparación y orden de números naturales

Counting Within 1,000 by Ones

Skip-Counting by 10s Within 1,000

Skip-Counting by 5s Within 1,000

Skip-Counting by 100s to 1,000

Skip-Counting by 2s to 100

Skip-Counting by 25s to 1,000

Skip-Counting and Counting Within 1,000

Understanding Hundreds, Tens, and Ones

Reading Three-Digit Number Names

Writing Three-Digit Numbers in Expanded Form

Identifying the Value of Digits in Three-Digit Numbers

Estimating Quantities up to 100 with Benchmarks

Estimating Quantities up to 1,000 with Referents

Even and Odd Numbers to 100

Even and Odd Numbers up to 1,000

Place Value, Representation, and Number Properties to 1,000

Ubicación de números en la recta numérica hasta 100

Redondeo a la decena más cercana en la recta numérica

Redondeo a la centena más cercana

Patrones de paridad en la tabla de multiplicar por 2

Patrones de múltiplos de cinco y diez

Resolución de acertijos numéricos con pistas de orden y posición

Recta numérica, redondeo y patrones numéricos

Skip Counting in 2s to 10 with Pairs

Skip Counting in 2s up to 20

Skip Counting in 5s to 20

Skip Counting in 10s to 50

Skip Counting in 10s to 100

Choosing the Best Counting Strategy

Skip Counting and Number Patterns

Finding 10 More and 10 Less Within 1,000

Finding 100 More and 100 Less Within 1,000

Rounding Numbers to the Nearest 10 Within 1,000

Rounding Numbers to the Nearest 100 Within 1,000

Solving Real-World Three-Digit Number Problems

Analyzing Quantities to 1,000 Capstone Challenge

Mental Math, Rounding, and Problem Solving Within 1,000

Conceptual Subitising: Seeing Parts in 6

Conceptual Subitising: Seeing Parts in 7 and 8

Conceptual Subitising on Ten-Frames up to 10

Comparing Quantities with Matching Towers

Comparing Numbers Using 'More Than' and 'Less Than' to 10

Comparing Numbers With Different Tens Digits

Comparing Two-Digit Numbers With Base-Ten Models

Subitising and Comparing Quantities to 20

OGM.1.NBT.2

Aligned learning resources

Related diagrams