<!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>Interpreting Expressions Diagram</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      background-color: #f8fafc;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      color: #0f172a;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
      padding: 16px;
      user-select: none;
    }

    .diagram-wrap {
      width: 100%;
      max-width: 580px;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .expression-row {
      display: flex;
      align-items: stretch;
      justify-content: center;
      gap: 10px;
      position: relative;
    }

    .term-card {
      flex: 1;
      background: #ffffff;
      border-radius: 12px;
      padding: 14px 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      box-shadow: 0 2px 8px rgba(15, 23, 42, 0.06);
      transition: transform 0.2s ease, box-shadow 0.2s ease;
      position: relative;
      border: 1px solid rgba(0,0,0,0.04);
    }

    .term-card.indigo {
      border-top: 4px solid #4f46e5;
    }

    .term-card.emerald {
      border-top: 4px solid #10b981;
    }

    .header-badge {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      font-size: 20px;
      font-weight: 800;
      margin-bottom: 12px;
      letter-spacing: -0.5px;
    }

    .indigo .header-badge {
      color: #4f46e5;
    }

    .emerald .header-badge {
      color: #10b981;
    }

    .factors-grid {
      display: flex;
      flex-direction: column;
      gap: 8px;
      width: 100%;
    }

    .factor-pill {
      background: #f1f5f9;
      border-radius: 8px;
      padding: 8px 10px;
      display: flex;
      align-items: center;
      gap: 8px;
      text-align: left;
    }

    .symbol {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 28px;
      height: 28px;
      border-radius: 6px;
      font-weight: 700;
      font-size: 15px;
      flex-shrink: 0;
    }

    .indigo .sym-const {
      background: #e0e7ff;
      color: #4338ca;
    }

    .indigo .sym-var {
      background: #ede9fe;
      color: #6366f1;
    }

    .emerald .sym-const {
      background: #d1fae5;
      color: #065f46;
    }

    .emerald .sym-var {
      background: #ccfbf1;
      color: #0d9488;
    }

    .factor-desc {
      font-size: 13px;
      font-weight: 600;
      line-height: 1.25;
      color: #334155;
    }

    .sub-note {
      font-size: 11px;
      font-weight: 500;
      color: #64748b;
      display: block;
    }

    .plus-operator {
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 24px;
      font-weight: 700;
      color: #64748b;
      padding: 0 4px;
    }

    /* Bottom Bracket Area */
    .bracket-section {
      display: flex;
      flex-direction: column;
      align-items: center;
      width: 100%;
      padding-top: 4px;
    }

    .bracket-svg {
      width: 100%;
      height: 22px;
      stroke: #64748b;
      stroke-width: 2;
      fill: none;
      stroke-linecap: round;
      stroke-linejoin: round;
    }

    .total-banner {
      margin-top: 6px;
      background: #0f172a;
      color: #f8fafc;
      padding: 6px 14px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 700;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      letter-spacing: 0.2px;
    }

    @media (max-width: 440px) {
      .term-card {
        padding: 10px 8px;
      }
      .factor-pill {
        padding: 6px 8px;
        gap: 6px;
      }
      .factor-desc {
        font-size: 11.5px;
      }
      .sub-note {
        font-size: 10px;
      }
      .header-badge {
        font-size: 18px;
      }
      .total-banner {
        font-size: 12px;
        padding: 5px 12px;
      }
    }
  </style>
</head>
<body>

  <div class="diagram-wrap">
    
    <div class="expression-row">
      
      <div class="term-card indigo">
        <div class="header-badge">
          <span>👤</span>
          <span>12a</span>
        </div>
        <div class="factors-grid">
          <div class="factor-pill">
            <span class="symbol sym-const">12</span>
            <div class="factor-desc">
              Adult price ($)
              <span class="sub-note">per ticket</span>
            </div>
          </div>
          <div class="factor-pill">
            <span class="symbol sym-var">a</span>
            <div class="factor-desc">
              Adult tickets
              <span class="sub-note">quantity sold</span>
            </div>
          </div>
        </div>
      </div>

      
      <div class="plus-operator">+</div>

      
      <div class="term-card emerald">
        <div class="header-badge">
          <span>🎒</span>
          <span>5s</span>
        </div>
        <div class="factors-grid">
          <div class="factor-pill">
            <span class="symbol sym-const">5</span>
            <div class="factor-desc">
              Student price ($)
              <span class="sub-note">per ticket</span>
            </div>
          </div>
          <div class="factor-pill">
            <span class="symbol sym-var">s</span>
            <div class="factor-desc">
              Student tickets
              <span class="sub-note">quantity sold</span>
            </div>
          </div>
        </div>
      </div>
    </div>

    
    <div class="bracket-section">
      <svg class="bracket-svg" viewBox="0 0 400 20" preserveAspectRatio="none">
        <path d="M 10 4 
                 C 10 14, 180 14, 195 14 
                 L 200 18 
                 L 205 14 
                 C 220 14, 390 14, 390 4" />
      </svg>
      <div class="total-banner">
        <span>Total Ticket Revenue ($)</span>
      </div>
    </div>
  </div>

</body>
</html>

Interpreting Expressions in Real-World Context

<!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: #ffffff;
      color: #1e2945;
      padding: 16px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
    }

    .main {
      width: 100%;
      max-width: 580px;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    /* Equation Rows */
    .row-card {
      background: #f8fafc;
      border: 2px solid #e2e8f0;
      border-radius: 12px;
      padding: 14px 16px;
      display: flex;
      flex-direction: column;
      gap: 10px;
      transition: border-color 0.25s, background-color 0.25s;
    }

    .row-card.highlight {
      border-color: #22b7ff;
      background: #f0f9ff;
    }

    .form-title {
      font-size: 11px;
      font-weight: 700;
      letter-spacing: 0.05em;
      text-transform: uppercase;
      color: #64748b;
    }

    .expr-container {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 12px;
      flex-wrap: wrap;
    }

    .term-group {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 4px;
      position: relative;
    }

    .term-math {
      font-size: 26px;
      font-weight: 800;
      padding: 4px 10px;
      border-radius: 8px;
      background: #ffffff;
      box-shadow: 0 1px 3px rgba(0,0,0,0.06);
      border: 1.5px solid transparent;
      display: flex;
      align-items: center;
    }

    .term-math.blue { color: #0284c7; border-color: #bae6fd; background: #f0f9ff; }
    .term-math.teal { color: #0d9488; border-color: #99f6e4; background: #f0fdfa; }
    .term-math.amber { color: #d97706; border-color: #fde68a; background: #fffbeb; }

    .term-label {
      font-size: 12px;
      font-weight: 600;
      color: #475569;
      text-align: center;
      line-height: 1.2;
    }

    .sub-calc {
      font-size: 11px;
      font-weight: 500;
      color: #94a3b8;
    }

    .symbol {
      font-size: 24px;
      font-weight: 700;
      color: #94a3b8;
    }

    /* Equal Divider */
    .equal-divider {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      font-size: 13px;
      font-weight: 700;
      color: #0284c7;
      padding: 2px 0;
    }

    .equal-badge {
      background: #e0f2fe;
      color: #0369a1;
      padding: 4px 12px;
      border-radius: 20px;
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }

    /* Live Calculator Footer */
    .calc-bar {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 10px;
      padding: 10px 14px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
      font-size: 13px;
    }

    .slider-box {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 600;
      color: #334155;
      flex: 1;
    }

    input[type=range] {
      flex: 1;
      accent-color: #0284c7;
      cursor: pointer;
      min-width: 60px;
    }

    .result-pill {
      background: #ecfdf5;
      border: 1px solid #a7f3d0;
      color: #047857;
      font-weight: 700;
      padding: 4px 10px;
      border-radius: 6px;
      white-space: nowrap;
    }
  </style>
</head>
<body>

  <div class="main">
    
    <div class="row-card" id="cardFactored">
      <div class="form-title">Factored Form</div>
      <div class="expr-container">
        
        <div class="term-group">
          <div class="term-math blue">4</div>
          <div class="term-label">4 Shirts</div>
        </div>

        <div class="symbol">×</div>

        
        <div class="term-group">
          <div class="term-math teal">(p − 3)</div>
          <div class="term-label">Discounted Shirt Price</div>
        </div>
      </div>
    </div>

    
    <div class="equal-divider">
      <div class="equal-badge">
        <span>=</span>
        <span>Same Total Cost</span>
      </div>
    </div>

    
    <div class="row-card" id="cardExpanded">
      <div class="form-title">Expanded Form (Distributed)</div>
      <div class="expr-container">
        
        <div class="term-group">
          <div class="term-math blue">4p</div>
          <div class="term-label">Original Total</div>
        </div>

        <div class="symbol">−</div>

        
        <div class="term-group">
          <div class="term-math amber">12</div>
          <div class="term-label">Total Savings<br><span class="sub-calc">(4 × $3)</span></div>
        </div>
      </div>
    </div>

    
    <div class="calc-bar">
      <div class="slider-box">
        <label for="priceSlider">Try p = $<span id="pVal">20</span></label>
        <input type="range" id="priceSlider" min="5" max="50" step="1" value="20">
      </div>
      <div class="result-pill" id="resultDisplay">
        Both = $68
      </div>
    </div>
  </div>

  <script>
    const slider = document.getElementById('priceSlider');
    const pVal = document.getElementById('pVal');
    const resultDisplay = document.getElementById('resultDisplay');

    function update() {
      const p = parseInt(slider.value, 10);
      pVal.textContent = p;
      const total = 4 * (p - 3);
      resultDisplay.textContent = `Both = $${total}`;
    }

    slider.addEventListener('input', update);
    update();
  </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="1:1">
  <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: transparent;
      padding: 12px;
      display: flex;
      justify-content: center;
    }
    .diagram {
      width: 100%;
      max-width: 460px;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    /* Expression Header */
    .expr-display {
      display: flex;
      justify-content: center;
      align-items: center;
      gap: 8px;
      font-size: 32px;
      font-weight: 800;
      letter-spacing: -0.5px;
    }
    .term-const {
      color: #b43403;
      background: #fef3c7;
      padding: 2px 10px;
      border-radius: 8px;
      border-bottom: 3px solid #d97706;
    }
    .op-plus {
      color: #94a3b8;
      font-weight: 500;
    }
    .term-var {
      color: #0284c7;
      background: #f0f9ff;
      padding: 2px 10px;
      border-radius: 8px;
      border-bottom: 3px solid #0284c7;
    }

    /* Cards */
    .cards-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 10px;
    }
    .annot-card {
      padding: 8px 10px;
      border-radius: 8px;
      font-size: 13px;
      line-height: 1.35;
    }
    .annot-card.const {
      background: #fffbeb;
      border: 1px solid #fde68a;
      color: #92400e;
    }
    .annot-card.var {
      background: #f0f9ff;
      border: 1px solid #bae6fd;
      color: #0369a1;
    }
    .card-title {
      font-weight: 700;
      font-size: 13px;
      margin-bottom: 2px;
      display: flex;
      align-items: center;
      gap: 4px;
    }
    .card-sub {
      font-size: 12px;
      opacity: 0.9;
    }

    /* Visual Simulation */
    .sim-panel {
      display: flex;
      align-items: center;
      justify-content: space-around;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 12px 8px;
      gap: 8px;
    }
    .pizza-wrap {
      width: 120px;
      height: 120px;
      flex-shrink: 0;
    }
    .topping-group {
      transition: opacity 0.25s ease, transform 0.25s ease;
      transform-origin: center;
    }
    .topping-group.hidden {
      opacity: 0;
      transform: scale(0.4);
      pointer-events: none;
    }

    /* Calculation Display */
    .calc-wrap {
      display: flex;
      flex-direction: column;
      gap: 4px;
      text-align: left;
    }
    .calc-step {
      font-size: 14px;
      font-family: ui-monospace, monospace;
      color: #475569;
    }
    .calc-step span {
      font-weight: 700;
    }
    .calc-step .c-const { color: #b43403; }
    .calc-step .c-var { color: #0284c7; }
    .total-badge {
      font-size: 22px;
      font-weight: 800;
      color: #0f172a;
      margin-top: 2px;
    }
    .total-badge span {
      color: #0284c7;
    }

    /* Controls */
    .controls {
      display: flex;
      flex-direction: column;
      gap: 6px;
      align-items: center;
    }
    .controls-label {
      font-size: 13px;
      font-weight: 600;
      color: #475569;
    }
    .btn-group {
      display: flex;
      gap: 6px;
      width: 100%;
      max-width: 380px;
    }
    .pill-btn {
      flex: 1;
      padding: 8px 4px;
      font-size: 14px;
      font-weight: 700;
      font-family: inherit;
      border: 1px solid #cbd5e1;
      background: #ffffff;
      color: #334155;
      border-radius: 8px;
      cursor: pointer;
      transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
    }
    .pill-btn:hover {
      background: #f1f5f9;
    }
    .pill-btn.active {
      background: #0284c7;
      border-color: #0284c7;
      color: #ffffff;
    }
  </style>
</head>
<body>
  <div class="diagram">
    
    <div class="expr-display">
      <span class="term-const">14</span>
      <span class="op-plus">+</span>
      <span class="term-var">2t</span>
    </div>

    <div class="cards-row">
      <div class="annot-card const">
        <div class="card-title">Constant: 14</div>
        <div class="card-sub">Base plain pizza ($14 fixed cost)</div>
      </div>
      <div class="annot-card var">
        <div class="card-title">Variable Term: 2t</div>
        <div class="card-sub">$2 per topping &times; <b>t</b> toppings</div>
      </div>
    </div>

    
    <div class="sim-panel">
      <div class="pizza-wrap">
        <svg viewBox="0 0 120 120" width="120" height="120">
          
          <circle cx="60" cy="60" r="56" fill="#d97706" />
          <circle cx="60" cy="60" r="50" fill="#fef08a" stroke="#ca8a04" stroke-width="2" />
          
          <line x1="60" y1="10" x2="60" y2="110" stroke="#facc15" stroke-width="1.5" stroke-dasharray="3,3" />
          <line x1="10" y1="60" x2="110" y2="60" stroke="#facc15" stroke-width="1.5" stroke-dasharray="3,3" />
          <line x1="25" y1="25" x2="95" y2="95" stroke="#facc15" stroke-width="1.5" stroke-dasharray="3,3" />
          <line x1="25" y1="95" x2="95" y2="25" stroke="#facc15" stroke-width="1.5" stroke-dasharray="3,3" />

          
          <g id="top-1" class="topping-group hidden">
            <circle cx="42" cy="40" r="7" fill="#dc2626" />
            <circle cx="78" cy="44" r="7" fill="#dc2626" />
            <circle cx="58" cy="78" r="7" fill="#dc2626" />
          </g>

          
          <g id="top-2" class="topping-group hidden">
            <ellipse cx="60" cy="36" rx="6" ry="4" fill="#78716c" />
            <rect x="58" y="38" width="4" height="4" fill="#a8a29e" rx="1" />
            <ellipse cx="40" cy="74" rx="6" ry="4" fill="#78716c" />
            <rect x="38" y="76" width="4" height="4" fill="#a8a29e" rx="1" />
            <ellipse cx="80" cy="72" rx="6" ry="4" fill="#78716c" />
            <rect x="78" y="74" width="4" height="4" fill="#a8a29e" rx="1" />
          </g>

          
          <g id="top-3" class="topping-group hidden">
            <rect x="46" y="52" width="10" height="4" rx="2" fill="#16a34a" transform="rotate(25 51 54)" />
            <rect x="68" y="54" width="10" height="4" rx="2" fill="#16a34a" transform="rotate(-30 73 56)" />
            <rect x="54" y="22" width="10" height="4" rx="2" fill="#16a34a" transform="rotate(70 59 24)" />
          </g>

          
          <g id="top-4" class="topping-group hidden">
            <circle cx="32" cy="56" r="4" fill="#1e293b" />
            <circle cx="32" cy="56" r="2" fill="#fef08a" />
            <circle cx="86" cy="56" r="4" fill="#1e293b" />
            <circle cx="86" cy="56" r="2" fill="#fef08a" />
            <circle cx="62" cy="94" r="4" fill="#1e293b" />
            <circle cx="62" cy="94" r="2" fill="#fef08a" />
          </g>
        </svg>
      </div>

      <div class="calc-wrap">
        <div class="calc-step">Cost = <span class="c-const">14</span> + <span class="c-var">2(<span id="t-val">0</span>)</span></div>
        <div class="calc-step">Cost = <span class="c-const">14</span> + <span class="c-var" id="var-sub">$0</span></div>
        <div class="total-badge">Total: <span id="total-val">$14</span></div>
      </div>
    </div>

    
    <div class="controls">
      <div class="controls-label">Choose toppings (t):</div>
      <div class="btn-group">
        <button class="pill-btn active" onclick="setToppings(0)">t = 0</button>
        <button class="pill-btn" onclick="setToppings(1)">t = 1</button>
        <button class="pill-btn" onclick="setToppings(2)">t = 2</button>
        <button class="pill-btn" onclick="setToppings(3)">t = 3</button>
        <button class="pill-btn" onclick="setToppings(4)">t = 4</button>
      </div>
    </div>
  </div>

  <script>
    function setToppings(t) {
      // Update buttons
      const buttons = document.querySelectorAll('.pill-btn');
      buttons.forEach((btn, idx) => {
        if (idx === t) {
          btn.classList.add('active');
        } else {
          btn.classList.remove('active');
        }
      });

      // Update pizza visual toppings
      for (let i = 1; i <= 4; i++) {
        const topEl = document.getElementById('top-' + i);
        if (topEl) {
          if (i <= t) {
            topEl.classList.remove('hidden');
          } else {
            topEl.classList.add('hidden');
          }
        }
      }

      // Update calculation readouts
      document.getElementById('t-val').textContent = t;
      document.getElementById('var-sub').textContent = '$' + (2 * t);
      document.getElementById('total-val').textContent = '$' + (14 + 2 * t);
    }
  </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;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    }
    body {
      background: #f8fafc;
      color: #1e2945;
      padding: 12px;
      display: flex;
      flex-direction: column;
      gap: 12px;
      user-select: none;
    }
    .grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 12px;
      width: 100%;
    }
    @media (max-width: 420px) {
      .grid {
        grid-template-columns: 1fr;
      }
    }
    .panel {
      background: #ffffff;
      border: 1.5px solid #e2e8f0;
      border-radius: 12px;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 220px;
    }
    .panel-header {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 4px;
      width: 100%;
    }
    .badge {
      font-size: 11px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.05em;
      padding: 3px 8px;
      border-radius: 6px;
    }
    .badge-expr {
      background: #eff6ff;
      color: #2563eb;
    }
    .badge-eq {
      background: #ecfdf5;
      color: #059669;
    }
    .math-title {
      font-size: 18px;
      font-weight: 700;
      color: #0f172a;
    }
    .canvas-area {
      width: 100%;
      height: 125px;
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
    }
    .caption {
      font-size: 12px;
      font-weight: 600;
      color: #64748b;
      text-align: center;
    }

    /* Controls bar */
    .controls {
      background: #ffffff;
      border: 1.5px solid #e2e8f0;
      border-radius: 12px;
      padding: 8px 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 12px;
    }
    .controls label {
      font-size: 13px;
      font-weight: 700;
      color: #334155;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .val-tag {
      display: inline-block;
      min-width: 22px;
      text-align: center;
      background: #0ea5e9;
      color: #ffffff;
      padding: 1px 6px;
      border-radius: 4px;
      font-size: 13px;
    }
    input[type=range] {
      flex: 1;
      max-width: 200px;
      accent-color: #0ea5e9;
      cursor: pointer;
    }

    /* SVG scale & weight styles */
    svg {
      overflow: visible;
    }
    .beam {
      transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1);
      transform-origin: 100px 32px;
    }
    .pan-left, .pan-right {
      transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1);
    }
  </style>
</head>
<body>

  <div class="grid">
    
    <div class="panel">
      <div class="panel-header">
        <span class="badge badge-expr">Expression</span>
        <div class="math-title">2x + 7</div>
      </div>

      <div class="canvas-area">
        <svg width="180" height="110" viewBox="0 0 180 110">
          
          <rect x="15" y="85" width="150" height="6" rx="3" fill="#cbd5e1"/>
          <line x1="35" y1="91" x2="35" y2="105" stroke="#94a3b8" stroke-width="4" stroke-linecap="round"/>
          <line x1="145" y1="91" x2="145" y2="105" stroke="#94a3b8" stroke-width="4" stroke-linecap="round"/>
          
          
          <rect x="45" y="32" width="90" height="53" rx="8" fill="#3b82f6" stroke="#1d4ed8" stroke-width="2"/>
          <rect x="75" y="24" width="30" height="8" rx="3" fill="#1d4ed8"/>
          
          
          <text x="90" y="54" text-anchor="middle" fill="#ffffff" font-size="13" font-weight="700">2x + 7</text>
          <text id="exprVal" x="90" y="73" text-anchor="middle" fill="#bfdbfe" font-size="12" font-weight="700">= 15</text>
        </svg>
      </div>

      <div class="caption">A phrase &bull; Single value</div>
    </div>

    
    <div class="panel">
      <div class="panel-header">
        <span class="badge badge-eq">Equation</span>
        <div class="math-title">2x + 7 = 15</div>
      </div>

      <div class="canvas-area">
        <svg width="200" height="115" viewBox="0 0 200 115">
          
          <polygon points="100,32 85,98 115,98" fill="#cbd5e1"/>
          <rect x="75" y="98" width="50" height="6" rx="3" fill="#94a3b8"/>
          
          
          <g id="scaleBeam" class="beam">
            
            <line x1="25" y1="32" x2="175" y2="32" stroke="#475569" stroke-width="4" stroke-linecap="round"/>
            
            <circle cx="100" cy="32" r="13" fill="#10b981" stroke="#059669" stroke-width="2"/>
            <text id="eqSign" x="100" y="37" text-anchor="middle" fill="#ffffff" font-size="15" font-weight="800">=</text>
          </g>

          
          <g id="panLeft" class="pan-left">
            <line x1="25" y1="32" x2="10" y2="68" stroke="#94a3b8" stroke-width="1.5"/>
            <line x1="25" y1="32" x2="50" y2="68" stroke="#94a3b8" stroke-width="1.5"/>
            <path d="M 8 68 Q 30 78 52 68 Z" fill="#64748b"/>
            
            <rect x="13" y="47" width="34" height="20" rx="4" fill="#3b82f6"/>
            <text id="panLeftText" x="30" y="61" text-anchor="middle" fill="#ffffff" font-size="9" font-weight="700">15</text>
          </g>

          
          <g id="panRight" class="pan-right">
            <line x1="175" y1="32" x2="150" y2="68" stroke="#94a3b8" stroke-width="1.5"/>
            <line x1="175" y1="32" x2="190" y2="68" stroke="#94a3b8" stroke-width="1.5"/>
            <path d="M 148 68 Q 170 78 192 68 Z" fill="#64748b"/>
            
            <rect x="153" y="47" width="34" height="20" rx="4" fill="#10b981"/>
            <text x="170" y="61" text-anchor="middle" fill="#ffffff" font-size="9" font-weight="700">15</text>
          </g>
        </svg>
      </div>

      <div id="eqCaption" class="caption">A sentence &bull; Balanced</div>
    </div>
  </div>

  
  <div class="controls">
    <label>
      <span>Set x:</span>
      <span id="xDisplay" class="val-tag">4</span>
    </label>
    <input id="xSlider" type="range" min="1" max="7" value="4" step="1">
  </div>

  <script>
    const slider = document.getElementById('xSlider');
    const xDisplay = document.getElementById('xDisplay');
    const exprVal = document.getElementById('exprVal');
    const scaleBeam = document.getElementById('scaleBeam');
    const panLeft = document.getElementById('panLeft');
    const panRight = document.getElementById('panRight');
    const panLeftText = document.getElementById('panLeftText');
    const eqSign = document.getElementById('eqSign');
    const eqCaption = document.getElementById('eqCaption');

    function update() {
      const x = parseInt(slider.value, 10);
      const leftTotal = 2 * x + 7;
      const rightTotal = 15;

      xDisplay.textContent = x;
      exprVal.textContent = '= ' + leftTotal;
      panLeftText.textContent = leftTotal;

      if (leftTotal === rightTotal) {
        // Balanced
        scaleBeam.style.transform = 'rotate(0deg)';
        panLeft.style.transform = 'translateY(0px)';
        panRight.style.transform = 'translateY(0px)';
        eqSign.textContent = '=';
        eqSign.parentElement.querySelector('circle').setAttribute('fill', '#10b981');
        eqCaption.textContent = 'A sentence • Balanced';
        eqCaption.style.color = '#059669';
      } else if (leftTotal < rightTotal) {
        // Left side lighter (tilts up)
        const angle = -10;
        scaleBeam.style.transform = `rotate(${angle}deg)`;
        panLeft.style.transform = 'translateY(-13px)';
        panRight.style.transform = 'translateY(13px)';
        eqSign.textContent = '≠';
        eqSign.parentElement.querySelector('circle').setAttribute('fill', '#f59e0b');
        eqCaption.textContent = 'A sentence • Unbalanced';
        eqCaption.style.color = '#d97706';
      } else {
        // Left side heavier (tilts down)
        const angle = 10;
        scaleBeam.style.transform = `rotate(${angle}deg)`;
        panLeft.style.transform = 'translateY(13px)';
        panRight.style.transform = 'translateY(-13px)';
        eqSign.textContent = '≠';
        eqSign.parentElement.querySelector('circle').setAttribute('fill', '#f59e0b');
        eqCaption.textContent = 'A sentence • Unbalanced';
        eqCaption.style.color = '#d97706';
      }
    }

    slider.addEventListener('input', update);
    update();
  </script>
</body>
</html>

What Are Algebraic Expressions?

<!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;
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      cursor: pointer;
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      display: flex;
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      font-family: 'Times New Roman', Times, serif;
      letter-spacing: 0.2px;
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      background: #f0fdf4;
      border-color: #059669;
      color: #047857;
      box-shadow: 0 0 0 2px rgba(5, 150, 105, 0.2);
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    .flow-lanes {
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .lane {
      display: grid;
      grid-template-columns: minmax(85px, 1.2fr) auto minmax(110px, 1.6fr) auto minmax(85px, 1.2fr);
      align-items: center;
      gap: 8px;
      padding: 10px 12px;
      border-radius: 12px;
      border: 2px solid #cbd5e1;
      background: #f8fafc;
      transition: opacity 0.25s ease, border-color 0.25s ease, background-color 0.25s ease, box-shadow 0.25s ease;
      cursor: pointer;
      opacity: 0.75;
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    .lane.active {
      opacity: 1;
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    .lane.blue.active {
      border-color: #2563eb;
      background: #eff6ff;
      box-shadow: 0 4px 12px rgba(37, 99, 235, 0.12);
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      border-color: #7c3aed;
      background: #faf5ff;
      box-shadow: 0 4px 12px rgba(124, 58, 237, 0.12);
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    .lane.green.active {
      border-color: #059669;
      background: #f0fdf4;
      box-shadow: 0 4px 12px rgba(5, 150, 105, 0.12);
    }

    .math-expr {
      font-family: 'Times New Roman', Times, serif;
      font-size: clamp(13px, 2.9vw, 16px);
      font-weight: 700;
      letter-spacing: 0.3px;
      color: #0f172a;
      white-space: nowrap;
      text-align: center;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .condition-box {
      background: #ffffff;
      border: 1px solid #cbd5e1;
      border-radius: 8px;
      padding: 6px 8px;
      width: 100%;
    }

    .lane.active .condition-box {
      border-color: #94a3b8;
      box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    }

    .condition {
      font-size: clamp(10.5px, 2.2vw, 12px);
      font-weight: 600;
      color: #1e293b;
      line-height: 1.35;
      text-align: center;
    }

    .cond-line {
      display: block;
      white-space: nowrap;
    }

    .cond-sub {
      font-size: 0.92em;
      color: #475569;
      font-weight: 500;
    }

    .arrow {
      color: #64748b;
      font-size: 16px;
      font-weight: 800;
      line-height: 1;
      user-select: none;
    }

    .lane.blue.active .arrow { color: #2563eb; }
    .lane.purple.active .arrow { color: #7c3aed; }
    .lane.green.active .arrow { color: #059669; }

    .badge {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      padding: 6px 6px;
      border-radius: 8px;
      font-size: clamp(10.5px, 2.2vw, 12px);
      font-weight: 700;
      text-align: center;
      line-height: 1.25;
      border: 1px solid transparent;
      width: 100%;
      white-space: nowrap;
    }

    .badge-blue {
      background: #dbeafe;
      color: #1e40af;
      border-color: #bfdbfe;
    }
    .badge-purple {
      background: #ede9fe;
      color: #5b21b6;
      border-color: #ddd6fe;
    }
    .badge-green {
      background: #d1fae5;
      color: #065f46;
      border-color: #a7f3d0;
    }

    .var-highlight {
      color: #6d28d9;
      font-weight: 800;
      font-style: italic;
    }
    .eq-highlight {
      color: #047857;
      font-weight: 800;
    }

    @media (max-width: 420px) {
      body { padding: 8px; gap: 8px; }
      .lane { padding: 8px 6px; gap: 4px; grid-template-columns: minmax(76px, 1.2fr) auto minmax(95px, 1.7fr) auto minmax(76px, 1.2fr); }
      .condition-box { padding: 4px 3px; }
      .arrow { font-size: 13px; }
    }
  </style>
</head>
<body>

  <div class="nav-tabs">
    <button class="tab-btn blue active" id="tab0">4 × (6 − 1)</button>
    <button class="tab-btn purple" id="tab1">5<i>y</i> − 9</button>
    <button class="tab-btn green" id="tab2">5<i>y</i> − 9 = 21</button>
  </div>

  <div class="flow-lanes">
    
    <div class="lane blue active" id="lane0">
      <div class="math-expr">4 × (6 − 1)</div>
      <div class="arrow">→</div>
      <div class="condition-box">
        <div class="condition">
          <span class="cond-line">Numbers only: <strong>Yes</strong></span>
          <span class="cond-line cond-sub">Equals sign: <strong>No</strong></span>
        </div>
      </div>
      <div class="arrow">→</div>
      <div class="badge badge-blue">
        <span>Numerical</span>
        <span>Expression</span>
      </div>
    </div>

    
    <div class="lane purple" id="lane1">
      <div class="math-expr">5<span class="var-highlight">y</span>&nbsp;−&nbsp;9</div>
      <div class="arrow">→</div>
      <div class="condition-box">
        <div class="condition">
          <span class="cond-line">Has variable (<span class="var-highlight">y</span>): <strong>Yes</strong></span>
          <span class="cond-line cond-sub">Equals sign: <strong>No</strong></span>
        </div>
      </div>
      <div class="arrow">→</div>
      <div class="badge badge-purple">
        <span>Algebraic</span>
        <span>Expression</span>
      </div>
    </div>

    
    <div class="lane green" id="lane2">
      <div class="math-expr">5<i>y</i>&nbsp;−&nbsp;9&nbsp;<span class="eq-highlight">=</span>&nbsp;21</div>
      <div class="arrow">→</div>
      <div class="condition-box">
        <div class="condition">
          <span class="cond-line">Has equals sign (<span class="eq-highlight">=</span>):</span>
          <span class="cond-line"><strong>Yes</strong></span>
        </div>
      </div>
      <div class="arrow">→</div>
      <div class="badge badge-green">
        <span>Equation</span>
      </div>
    </div>
  </div>

  <script>
    let activeIdx = 0;
    const total = 3;
    let timer = null;

    function selectIndex(idx) {
      activeIdx = idx;
      for (let i = 0; i < total; i++) {
        const tab = document.getElementById('tab' + i);
        const lane = document.getElementById('lane' + i);
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          tab.classList.add('active');
          lane.classList.add('active');
        } else {
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          lane.classList.remove('active');
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        selectIndex(i);
        startAutoCycle();
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      timer = setInterval(() => {
        activeIdx = (activeIdx + 1) % total;
        selectIndex(activeIdx);
      }, 3500);
    }

    startAutoCycle();
  </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;
      background: transparent;
      color: #1e2945;
      display: flex;
      justify-content: center;
      align-items: center;
      min-height: 100%;
      padding: 12px;
    }

    .diagram {
      width: 100%;
      max-width: 480px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 14px;
    }

    /* Top Real-World Section */
    .real-world {
      width: 100%;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 8px;
    }

    .item-card {
      flex: 1;
      background: #ffffff;
      border: 1px solid #e6e6e6;
      border-radius: 14px;
      padding: 12px 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 8px;
      box-shadow: 0 2px 6px rgba(0, 0, 0, 0.03);
    }

    .icon-row {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 4px;
      height: 38px;
    }

    .pizza-box {
      width: 32px;
      height: 32px;
      background: #fffbeb;
      border: 1.5px solid #f59e0b;
      border-radius: 6px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 16px;
      box-shadow: 0 2px 4px rgba(245, 158, 11, 0.15);
    }

    .scooter-box {
      width: 44px;
      height: 36px;
      background: #eff6ff;
      border: 1.5px solid #2563eb;
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 20px;
      box-shadow: 0 2px 4px rgba(37, 99, 235, 0.15);
    }

    .tag {
      font-size: 13px;
      font-weight: 700;
      padding: 3px 8px;
      border-radius: 20px;
      letter-spacing: -0.2px;
    }

    .tag-amber {
      background: #fef3c7;
      color: #b45309;
      border: 1px solid #fde68a;
    }

    .tag-blue {
      background: #dbeafe;
      color: #1d4ed8;
      border: 1px solid #bfdbfe;
    }

    .plus-divider {
      font-size: 22px;
      font-weight: 800;
      color: #94a3b8;
      user-select: none;
    }

    /* Linking arrows */
    .connector-svg {
      width: 100%;
      height: 24px;
      display: block;
      overflow: visible;
    }

    /* Bottom Math Card */
    .math-card {
      width: 100%;
      background: #ffffff;
      border: 1.5px solid #e6e6e6;
      border-radius: 16px;
      padding: 16px 14px 14px 14px;
      display: flex;
      flex-direction: column;
      align-items: center;
      position: relative;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.04);
    }

    .expression-box {
      display: inline-flex;
      align-items: baseline;
      justify-content: center;
      padding: 4px 16px;
      background: #f8fafc;
      border: 1.5px dashed #cbd5e1;
      border-radius: 10px;
      margin-bottom: 8px;
    }

    .math-text {
      font-size: 34px;
      font-weight: 800;
      letter-spacing: 0.5px;
      display: flex;
      align-items: baseline;
    }

    .num-part { color: #1e2945; }
    
    .var-wrapper {
      position: relative;
      display: inline-flex;
      flex-direction: column;
      align-items: center;
    }

    .var-part {
      color: #2563eb;
      background: #eff6ff;
      border: 1.5px solid #bfdbfe;
      border-radius: 6px;
      padding: 0 6px;
      margin: 0 2px;
    }

    .op-part {
      color: #64748b;
      margin: 0 6px;
    }

    .const-part {
      color: #b45309;
    }

    /* Callout annotations */
    .callout-var {
      margin-top: 6px;
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
    }

    .arrow-up {
      width: 0;
      height: 0;
      border-left: 5px solid transparent;
      border-right: 5px solid transparent;
      border-bottom: 6px solid #2563eb;
      margin-bottom: 2px;
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    .label-var {
      font-size: 13px;
      font-weight: 700;
      color: #2563eb;
      line-height: 1.2;
    }

    .total-badge {
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      padding-top: 8px;
      border-top: 1px solid #f1f5f9;
      width: 100%;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      font-size: 14px;
      font-weight: 700;
      color: #475569;
    }

    .bracket-indicator {
      font-size: 12px;
      color: #64748b;
      background: #f1f5f9;
      padding: 2px 8px;
      border-radius: 12px;
    }
  </style>
</head>
<body>
  <div class="diagram">
    
    <div class="real-world">
      <div class="item-card">
        <div class="icon-row">
          <div class="pizza-box">🍕</div>
          <div class="pizza-box">🍕</div>
          <div class="pizza-box">🍕</div>
        </div>
        <span class="tag tag-amber">$12 each</span>
      </div>

      <div class="plus-divider">+</div>

      <div class="item-card">
        <div class="icon-row">
          <div class="scooter-box">🛵</div>
        </div>
        <span class="tag tag-blue">+$4 fee</span>
      </div>
    </div>

    
    <svg class="connector-svg" viewBox="0 0 400 24" preserveAspectRatio="none">
      <path d="M 110 0 L 110 12 L 185 24" fill="none" stroke="#cbd5e1" stroke-width="1.5" stroke-dasharray="3,3" />
      <path d="M 290 0 L 290 12 L 235 24" fill="none" stroke="#cbd5e1" stroke-width="1.5" stroke-dasharray="3,3" />
      <polygon points="185,24 180,18 187,17" fill="#94a3b8" />
      <polygon points="235,24 233,17 240,18" fill="#94a3b8" />
    </svg>

    
    <div class="math-card">
      <div class="expression-box">
        <div class="math-text">
          <span class="num-part">12</span>
          <span class="var-wrapper">
            <span class="var-part">p</span>
          </span>
          <span class="op-part">+</span>
          <span class="const-part">4</span>
        </div>
      </div>

      
      <div class="callout-var">
        <div class="arrow-up"></div>
        <div class="label-var">Variable<br>(number of pizzas)</div>
      </div>

      
      <div class="total-badge">
        <span class="bracket-indicator">⎵ Entire Block</span>
        <span>Algebraic Expression (total cost)</span>
      </div>
    </div>
  </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">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      background: #f8f9fa;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      padding: 14px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
    }
    .grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 12px;
      width: 100%;
      max-width: 600px;
    }
    @media (max-width: 460px) {
      .grid {
        grid-template-columns: 1fr;
        gap: 10px;
      }
    }
    .col-card {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 16px 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      box-shadow: 0 1px 3px rgba(0,0,0,0.03);
    }
    .col-title {
      font-size: 13px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.5px;
      color: #64748b;
      margin-bottom: 12px;
    }
    .math-box {
      font-size: 24px;
      font-weight: 600;
      font-family: "Cambria Math", "KaTeX_Main", "Times New Roman", serif;
      padding: 8px 14px;
      background: #f8fafc;
      border: 1px solid #f1f5f9;
      border-radius: 8px;
      margin-bottom: 12px;
      letter-spacing: 1px;
    }
    .var-highlight {
      background: #fed7aa;
      color: #c2410c;
      padding: 2px 8px;
      border-radius: 6px;
      font-weight: 700;
      display: inline-block;
      transition: transform 0.2s ease;
    }
    .badge {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      font-size: 12px;
      font-weight: 700;
      padding: 4px 10px;
      border-radius: 20px;
      margin-bottom: 10px;
    }
    .badge-fixed {
      background: #dcfce7;
      color: #15803d;
      border: 1px solid #bbf7d0;
    }
    .badge-variable {
      background: #ffedd5;
      color: #c2410c;
      border: 1px solid #fed7aa;
    }
    .calc-row {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      font-size: 16px;
      font-weight: 600;
      color: #334155;
      font-family: "Cambria Math", "Times New Roman", serif;
    }
    .result-pill {
      background: #f1f5f9;
      border: 1px solid #cbd5e1;
      border-radius: 6px;
      padding: 2px 10px;
      font-weight: 700;
      color: #0f172a;
    }
    .interactive-row {
      display: flex;
      align-items: center;
      gap: 6px;
      margin-top: 4px;
    }
    .x-btn {
      background: #f8fafc;
      border: 1px solid #cbd5e1;
      border-radius: 6px;
      padding: 3px 8px;
      font-size: 12px;
      font-weight: 600;
      color: #475569;
      cursor: pointer;
      font-family: inherit;
      transition: all 0.15s ease;
    }
    .x-btn.active {
      background: #ea580c;
      border-color: #ea580c;
      color: #ffffff;
    }
  </style>
</head>
<body>
  <div class="grid">
    
    <div class="col-card">
      <div class="col-title">Numerical Expression</div>
      <div class="math-box">8 + 3 × 2</div>
      <div class="badge badge-fixed">✓ Fixed Value</div>
      <div class="calc-row">
        <span>= 8 + 6 =</span>
        <span class="result-pill">14</span>
      </div>
    </div>

    
    <div class="col-card">
      <div class="col-title">Algebraic Expression</div>
      <div class="math-box">3<span class="var-highlight" id="xDisplay">x</span> − 5</div>
      <div class="badge badge-variable">✦ Variable (can change)</div>
      <div class="interactive-row">
        <span style="font-size: 12px; color: #64748b; font-weight: 600;">If x =</span>
        <button class="x-btn active" id="btn2" onclick="setX(2)">2</button>
        <button class="x-btn" id="btn4" onclick="setX(4)">4</button>
        <button class="x-btn" id="btn10" onclick="setX(10)">10</button>
        <span style="font-size: 13px; font-weight: 700; margin-left: 2px;">→</span>
        <span class="result-pill" id="algebraicResult" style="color: #c2410c;">1</span>
      </div>
    </div>
  </div>

  <script>
    function setX(val) {
      document.querySelectorAll('.x-btn').forEach(btn => btn.classList.remove('active'));
      const activeBtn = document.getElementById('btn' + val);
      if (activeBtn) activeBtn.classList.add('active');
      
      const result = 3 * val - 5;
      const resEl = document.getElementById('algebraicResult');
      resEl.textContent = result;

      const xDisp = document.getElementById('xDisplay');
      xDisp.textContent = val;
      setTimeout(() => {
        xDisp.textContent = 'x';
      }, 450);
    }
  </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="1:1">
  <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: 8px;
      display: flex;
      flex-direction: column;
      height: 100%;
      user-select: none;
    }

    .grid-container {
      display: grid;
      grid-template-columns: 1fr 1fr;
      grid-template-rows: 1fr 1fr;
      gap: 8px;
      flex: 1;
      width: 100%;
      height: 100%;
    }

    .quadrant {
      border-radius: 12px;
      padding: 10px 12px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      transition: box-shadow 0.2s ease, border-color 0.2s ease;
      cursor: pointer;
      position: relative;
      overflow: hidden;
    }

    .quadrant:focus-visible,
    .quadrant:hover {
      box-shadow: 0 4px 12px rgba(30, 41, 69, 0.08);
    }

    /* Addition - Green */
    .quad-add {
      background: #f0fdf4;
      border: 1.5px solid #86efac;
    }
    .quad-add .sym-badge {
      background: #16a34a;
      color: #ffffff;
    }
    .quad-add .tag {
      background: #dcfce7;
      color: #15803d;
      border: 1px solid #bbf7d0;
    }
    .quad-add .highlight-target {
      color: #16a34a;
      font-weight: 700;
    }

    /* Subtraction - Rose/Red */
    .quad-sub {
      background: #fff1f2;
      border: 1.5px solid #fecdd3;
    }
    .quad-sub .sym-badge {
      background: #e11d48;
      color: #ffffff;
    }
    .quad-sub .tag {
      background: #ffe4e6;
      color: #be123c;
      border: 1px solid #fecdd3;
    }
    .quad-sub .tag-alert {
      background: #fee2e2;
      color: #b91c1c;
      border: 1px solid #f87171;
      font-weight: 700;
    }
    .quad-sub .highlight-target {
      color: #e11d48;
      font-weight: 700;
    }

    /* Multiplication - Blue */
    .quad-mul {
      background: #eff6ff;
      border: 1.5px solid #bfdbfe;
    }
    .quad-mul .sym-badge {
      background: #2563eb;
      color: #ffffff;
    }
    .quad-mul .tag {
      background: #dbeafe;
      color: #1d4ed8;
      border: 1px solid #bfdbfe;
    }
    .quad-mul .highlight-target {
      color: #2563eb;
      font-weight: 700;
    }

    /* Division - Amber/Orange */
    .quad-div {
      background: #fffbeb;
      border: 1.5px solid #fde68a;
    }
    .quad-div .sym-badge {
      background: #d97706;
      color: #ffffff;
    }
    .quad-div .tag {
      background: #fef3c7;
      color: #b45309;
      border: 1px solid #fde68a;
    }
    .quad-div .highlight-target {
      color: #d97706;
      font-weight: 700;
    }

    .quad-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 6px;
    }

    .quad-title {
      font-size: 13px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.5px;
      color: #1e2945;
    }

    .sym-badge {
      width: 26px;
      height: 26px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 17px;
      font-weight: 800;
      line-height: 1;
      flex-shrink: 0;
    }

    .tag-cloud {
      display: flex;
      flex-wrap: wrap;
      gap: 4px;
      margin: 4px 0;
    }

    .tag {
      font-size: 11px;
      font-weight: 600;
      padding: 2px 6px;
      border-radius: 6px;
      line-height: 1.2;
      white-space: nowrap;
    }

    .example-row {
      background: rgba(255, 255, 255, 0.85);
      border-radius: 8px;
      padding: 6px 8px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      font-size: 12px;
      border: 1px solid rgba(0, 0, 0, 0.05);
    }

    .phrase {
      color: #475569;
      font-weight: 500;
    }

    .arrow {
      color: #94a3b8;
      font-weight: bold;
      margin: 0 4px;
    }

    .math-expr {
      font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
      font-size: 13px;
      font-weight: 700;
      color: #1e2945;
      background: #ffffff;
      padding: 2px 6px;
      border-radius: 4px;
      border: 1px solid #cbd5e1;
    }

    .flip-note {
      font-size: 9.5px;
      color: #b91c1c;
      font-weight: 700;
      margin-left: 2px;
    }
  </style>
</head>
<body>
  <div class="grid-container">
    
    <div class="quadrant quad-add">
      <div class="quad-header">
        <span class="quad-title">Addition</span>
        <div class="sym-badge">+</div>
      </div>
      <div class="tag-cloud">
        <span class="tag">sum of</span>
        <span class="tag">increased by</span>
        <span class="tag">more than</span>
      </div>
      <div class="example-row">
        <span class="phrase">5 more than <span class="highlight-target">x</span></span>
        <span class="arrow">→</span>
        <span class="math-expr">x + 5</span>
      </div>
    </div>

    
    <div class="quadrant quad-sub">
      <div class="quad-header">
        <span class="quad-title">Subtraction</span>
        <div class="sym-badge">−</div>
      </div>
      <div class="tag-cloud">
        <span class="tag">difference</span>
        <span class="tag">decreased by</span>
        <span class="tag tag-alert">less than ⇄</span>
      </div>
      <div class="example-row">
        <span class="phrase">4 less than <span class="highlight-target">k</span></span>
        <span class="arrow">→</span>
        <span class="math-expr">k − 4</span>
      </div>
    </div>

    
    <div class="quadrant quad-mul">
      <div class="quad-header">
        <span class="quad-title">Multiplication</span>
        <div class="sym-badge">×</div>
      </div>
      <div class="tag-cloud">
        <span class="tag">product of</span>
        <span class="tag">times</span>
        <span class="tag">twice / of</span>
      </div>
      <div class="example-row">
        <span class="phrase">triple a number <span class="highlight-target">y</span></span>
        <span class="arrow">→</span>
        <span class="math-expr">3y</span>
      </div>
    </div>

    
    <div class="quadrant quad-div">
      <div class="quad-header">
        <span class="quad-title">Division</span>
        <div class="sym-badge">÷</div>
      </div>
      <div class="tag-cloud">
        <span class="tag">quotient of</span>
        <span class="tag">split equally</span>
        <span class="tag">ratio</span>
      </div>
      <div class="example-row">
        <span class="phrase">quotient of <span class="highlight-target">w</span> and 2</span>
        <span class="arrow">→</span>
        <span class="math-expr">w / 2</span>
      </div>
    </div>
  </div>
</body>
</html>

HSA.SSE.A.1

Child standards (2)

Aligned learning resources

Related diagrams