<!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 & Zero as a Placeholder</title>
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    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: space-between;
      min-height: 100vh;
      padding: 12px 10px;
    }

    .main-wrap {
      width: 100%;
      max-width: 560px;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    /* Blocks Display Row */
    .blocks-container {
      display: grid;
      grid-template-columns: 2.2fr 1fr 1fr;
      gap: 8px;
      background: #ffffff;
      border: 1.5px solid #e2e8f0;
      border-radius: 12px;
      padding: 10px;
      box-shadow: 0 1px 3px rgba(0,0,0,0.04);
    }

    .place-col {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: flex-start;
      gap: 6px;
      text-align: center;
    }

    .col-title {
      font-size: 13px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }
    .col-title.h-color { color: #2563eb; }
    .col-title.t-color { color: #059669; }
    .col-title.o-color { color: #d97706; }

    /* Base 10 visual elements */
    .flats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 4px;
      width: 100%;
      max-width: 180px;
      justify-items: center;
    }
    .flat-svg {
      width: 36px;
      height: 36px;
    }

    .rods-row {
      display: flex;
      gap: 8px;
      justify-content: center;
      align-items: center;
      height: 76px;
    }
    .rod-svg {
      width: 12px;
      height: 72px;
    }

    .empty-ones {
      height: 76px;
      width: 100%;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      border: 2px dashed #f59e0b;
      border-radius: 8px;
      background: #fffbeb;
      color: #b45309;
      font-size: 13px;
      font-weight: 700;
    }

    .count-tag {
      font-size: 12px;
      font-weight: 700;
      padding: 2px 8px;
      border-radius: 12px;
    }
    .h-tag { background: #eff6ff; color: #1d4ed8; }
    .t-tag { background: #ecfdf5; color: #047857; }
    .o-tag { background: #fffbeb; color: #b45309; }

    /* Slots & Total Row */
    .slots-card {
      background: #ffffff;
      border: 1.5px solid #e2e8f0;
      border-radius: 12px;
      padding: 10px 14px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 8px;
    }

    .slots-group {
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .slot-box {
      width: 52px;
      height: 58px;
      border-radius: 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      border: 2px solid #cbd5e1;
      background: #f8fafc;
      transition: all 0.2s ease;
    }

    .slot-box.h-slot { border-color: #93c5fd; background: #eff6ff; }
    .slot-box.t-slot { border-color: #a7f3d0; background: #ecfdf5; }
    .slot-box.o-slot {
      border-color: #fcd34d;
      background: #fffbeb;
      box-shadow: 0 0 0 3px rgba(245, 158, 11, 0.25);
      position: relative;
    }

    .slot-digit {
      font-size: 22px;
      font-weight: 800;
      line-height: 1;
    }
    .h-slot .slot-digit { color: #1d4ed8; }
    .t-slot .slot-digit { color: #047857; }
    .o-slot .slot-digit { color: #d97706; }

    .slot-lbl {
      font-size: 10px;
      font-weight: 700;
      text-transform: uppercase;
      margin-top: 2px;
      color: #64748b;
    }

    .arrow-eq {
      font-size: 20px;
      font-weight: 800;
      color: #64748b;
    }

    .total-display {
      background: #0f172a;
      color: #ffffff;
      padding: 8px 16px;
      border-radius: 10px;
      font-size: 24px;
      font-weight: 800;
      letter-spacing: 2px;
    }

    /* Callout pointer */
    .callout-box {
      background: #fef3c7;
      border: 1.5px solid #f59e0b;
      border-radius: 10px;
      padding: 8px 12px;
      display: flex;
      align-items: center;
      gap: 8px;
      color: #92400e;
      font-size: 13px;
      font-weight: 700;
    }

    .callout-icon {
      font-size: 16px;
      line-height: 1;
    }

    /* Toggle bar */
    .toggle-bar {
      display: flex;
      gap: 8px;
      width: 100%;
    }

    .tab-btn {
      flex: 1;
      padding: 8px 10px;
      border-radius: 8px;
      font-size: 12px;
      font-weight: 700;
      border: 1.5px solid #cbd5e1;
      background: #ffffff;
      color: #475569;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
    }

    .tab-btn.active {
      background: #0284c7;
      border-color: #0284c7;
      color: #ffffff;
    }

    .warning-badge {
      background: #fee2e2;
      color: #dc2626;
      font-size: 10px;
      padding: 1px 5px;
      border-radius: 4px;
    }
  </style>
</head>
<body>

  <div class="main-wrap">
    
    <div class="toggle-bar">
      <button class="tab-btn active" id="btnWithZero" onclick="setMode(true)">
        <span>Standard: 720</span>
      </button>
      <button class="tab-btn" id="btnNoZero" onclick="setMode(false)">
        <span>Without 0: 72</span>
        <span class="warning-badge">Missing Zero!</span>
      </button>
    </div>

    
    <div class="blocks-container">
      
      <div class="place-col">
        <div class="col-title h-color">Hundreds</div>
        <div class="flats-grid" id="flatsGrid">
          
        </div>
        <span class="count-tag h-tag" id="hValue">7 flats = 700</span>
      </div>

      
      <div class="place-col">
        <div class="col-title t-color">Tens</div>
        <div class="rods-row" id="rodsRow">
          
        </div>
        <span class="count-tag t-tag" id="tValue">2 rods = 20</span>
      </div>

      
      <div class="place-col">
        <div class="col-title o-color">Ones</div>
        <div class="empty-ones" id="onesBox">
          <span style="font-size: 18px;">∅</span>
          <span>0 cubes</span>
        </div>
        <span class="count-tag o-tag" id="oValue">0 ones = 0</span>
      </div>
    </div>

    
    <div class="slots-card">
      <div class="slots-group">
        <div class="slot-box h-slot" id="slotH">
          <span class="slot-digit" id="digitH">7</span>
          <span class="slot-lbl" id="lblH">Hund.</span>
        </div>
        <div class="slot-box t-slot" id="slotT">
          <span class="slot-digit" id="digitT">2</span>
          <span class="slot-lbl" id="lblT">Tens</span>
        </div>
        <div class="slot-box o-slot" id="slotO">
          <span class="slot-digit" id="digitO">0</span>
          <span class="slot-lbl" id="lblO">Ones</span>
        </div>
      </div>

      <div class="arrow-eq">➔</div>

      <div class="total-display" id="totalNumber">720</div>
    </div>

    
    <div class="callout-box" id="calloutMsg">
      <span class="callout-icon">📌</span>
      <span id="calloutText">Zero holds the ones place! Without it, 720 becomes 72.</span>
    </div>
  </div>

  <script>
    // Create 10x10 Flat SVG
    function createFlatSVG() {
      return `
        <svg class="flat-svg" viewBox="0 0 40 40">
          <rect x="1" y="1" width="38" height="38" rx="2" fill="#bfdbfe" stroke="#2563eb" stroke-width="1.5"/>
          <path d="M 5 1 v 38 M 9 1 v 38 M 13 1 v 38 M 17 1 v 38 M 21 1 v 38 M 25 1 v 38 M 29 1 v 38 M 33 1 v 38 M 37 1 v 38
                   M 1 5 h 38 M 1 9 h 38 M 1 13 h 38 M 1 17 h 38 M 1 21 h 38 M 1 25 h 38 M 1 29 h 38 M 1 33 h 38 M 1 37 h 38"
                stroke="#60a5fa" stroke-width="0.75" />
        </svg>
      `;
    }

    // Create 1x10 Rod SVG
    function createRodSVG() {
      return `
        <svg class="rod-svg" viewBox="0 0 10 70">
          <rect x="0.5" y="0.5" width="9" height="69" rx="1.5" fill="#a7f3d0" stroke="#059669" stroke-width="1"/>
          <path d="M 0.5 7 h 9 M 0.5 14 h 9 M 0.5 21 h 9 M 0.5 28 h 9 M 0.5 35 h 9 M 0.5 42 h 9 M 0.5 49 h 9 M 0.5 56 h 9 M 0.5 63 h 9"
                stroke="#34d399" stroke-width="0.8" />
        </svg>
      `;
    }

    // Render initial base 10 blocks
    const flatsGrid = document.getElementById('flatsGrid');
    flatsGrid.innerHTML = Array(7).fill(createFlatSVG()).join('');

    const rodsRow = document.getElementById('rodsRow');
    rodsRow.innerHTML = Array(2).fill(createRodSVG()).join('');

    function setMode(withZero) {
      const btnWith = document.getElementById('btnWithZero');
      const btnNo = document.getElementById('btnNoZero');
      const digitH = document.getElementById('digitH');
      const digitT = document.getElementById('digitT');
      const digitO = document.getElementById('digitO');
      const slotH = document.getElementById('slotH');
      const slotT = document.getElementById('slotT');
      const slotO = document.getElementById('slotO');
      const totalNumber = document.getElementById('totalNumber');
      const calloutMsg = document.getElementById('calloutMsg');
      const calloutText = document.getElementById('calloutText');

      if (withZero) {
        btnWith.classList.add('active');
        btnNo.classList.remove('active');

        digitH.textContent = '7';
        digitT.textContent = '2';
        digitO.textContent = '0';
        slotO.style.display = 'flex';
        totalNumber.textContent = '720';
        totalNumber.style.background = '#0f172a';

        slotH.className = 'slot-box h-slot';
        slotT.className = 'slot-box t-slot';
        slotO.className = 'slot-box o-slot';

        calloutMsg.style.background = '#fef3c7';
        calloutMsg.style.borderColor = '#f59e0b';
        calloutMsg.style.color = '#92400e';
        calloutText.textContent = 'Zero holds the ones place! Without it, 720 becomes 72.';
      } else {
        btnNo.classList.add('active');
        btnWith.classList.remove('active');

        digitH.textContent = '7';
        digitT.textContent = '2';
        slotO.style.display = 'none';
        totalNumber.textContent = '72';
        totalNumber.style.background = '#dc2626';

        slotH.className = 'slot-box t-slot';
        document.getElementById('lblH').textContent = 'Tens';
        slotT.className = 'slot-box o-slot';
        document.getElementById('lblT').textContent = 'Ones';

        calloutMsg.style.background = '#fee2e2';
        calloutMsg.style.borderColor = '#ef4444';
        calloutMsg.style.color = '#991b1b';
        calloutText.textContent = 'Without zero, 7 hundreds + 2 tens collapsed into just 72!';
      }

      if (withZero) {
        document.getElementById('lblH').textContent = 'Hund.';
        document.getElementById('lblT').textContent = 'Tens';
      }
    }
  </script>
</body>
</html>

Reading and Writing Three-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">
  <title>Placeholder Zero in Place Value</title>
  <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: 12px;
      display: flex;
      flex-direction: column;
      gap: 12px;
      user-select: none;
    }

    /* Tab Switcher */
    .controls {
      display: flex;
      justify-content: center;
      gap: 8px;
    }
    .tab-btn {
      padding: 6px 14px;
      font-size: 14px;
      font-weight: 600;
      border-radius: 20px;
      border: 1px solid #cbd5e1;
      background: #f8fafc;
      color: #475569;
      cursor: pointer;
      transition: all 0.2s ease;
    }
    .tab-btn.active {
      background: #0284c7;
      color: #ffffff;
      border-color: #0284c7;
      box-shadow: 0 2px 6px rgba(2, 132, 199, 0.25);
    }

    /* Cards Layout */
    .cards-container {
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .num-card {
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 12px 14px;
      display: flex;
      flex-direction: column;
      gap: 10px;
      transition: opacity 0.3s ease, transform 0.3s ease;
    }
    .num-card.dimmed {
      opacity: 0.35;
    }

    /* Top: Expanded Equation */
    .equation-row {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      font-size: 16px;
      font-weight: 700;
      flex-wrap: wrap;
    }
    .term {
      padding: 4px 10px;
      border-radius: 8px;
      background: #ffffff;
      border: 1px solid #cbd5e1;
      color: #334155;
      font-variant-numeric: tabular-nums;
    }
    .term.h-term {
      background: #e0f2fe;
      border-color: #7dd3fc;
      color: #0369a1;
    }
    .term.t-term {
      background: #f1f5f9;
      border-color: #cbd5e1;
      color: #475569;
    }
    .term.o-term {
      background: #f1f5f9;
      border-color: #cbd5e1;
      color: #475569;
    }
    .term.zero-highlight {
      background: #fef3c7;
      border-color: #f59e0b;
      color: #b45309;
      box-shadow: 0 0 0 2px rgba(245, 158, 11, 0.2);
    }
    .symbol {
      color: #94a3b8;
      font-size: 15px;
    }
    .result {
      padding: 4px 12px;
      background: #0f172a;
      color: #ffffff;
      border-radius: 8px;
      font-weight: 800;
      font-size: 17px;
      letter-spacing: 1px;
    }

    /* Middle: Flow Connector */
    .flow-arrow {
      text-align: center;
      color: #94a3b8;
      font-size: 13px;
      line-height: 1;
    }

    /* Bottom: Place Value Table & Focus Badge */
    .pvc-row {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 12px;
      flex-wrap: wrap;
    }

    .pvc-table {
      display: grid;
      grid-template-columns: repeat(3, 56px);
      background: #ffffff;
      border: 2px solid #cbd5e1;
      border-radius: 10px;
      overflow: hidden;
      box-shadow: 0 2px 4px rgba(0, 0, 0, 0.04);
    }
    .pvc-col {
      display: flex;
      flex-direction: column;
      text-align: center;
    }
    .pvc-col:not(:last-child) {
      border-right: 1px solid #e2e8f0;
    }
    .pvc-head {
      font-size: 12px;
      font-weight: 700;
      padding: 4px 0;
      background: #f1f5f9;
      color: #64748b;
      border-bottom: 1px solid #e2e8f0;
    }
    .pvc-val {
      font-size: 20px;
      font-weight: 800;
      padding: 6px 0;
      color: #1e2945;
      font-variant-numeric: tabular-nums;
    }

    /* Zero Highlight in Table */
    .pvc-col.zero-col {
      background: #fffbeb;
    }
    .pvc-col.zero-col .pvc-head {
      background: #fef3c7;
      color: #b45309;
    }
    .pvc-col.zero-col .pvc-val {
      color: #d97706;
      font-size: 22px;
    }

    /* Pointer Callout */
    .zero-badge {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      background: #fef3c7;
      border: 1.5px solid #f59e0b;
      color: #92400e;
      padding: 6px 12px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 700;
    }
    .zero-badge span {
      font-size: 15px;
    }
  </style>
</head>
<body>

  
  <div class="controls">
    <button class="tab-btn active" onclick="setMode('all')">Show Both</button>
    <button class="tab-btn" onclick="setMode('tens')">406 (0 Tens)</button>
    <button class="tab-btn" onclick="setMode('ones')">780 (0 Ones)</button>
  </div>

  <div class="cards-container">
    
    <div class="num-card" id="card-tens">
      <div class="equation-row">
        <span class="term h-term">400</span>
        <span class="symbol">+</span>
        <span class="term zero-highlight">0</span>
        <span class="symbol">+</span>
        <span class="term o-term">6</span>
        <span class="symbol">=</span>
        <span class="result">406</span>
      </div>

      <div class="flow-arrow">▼</div>

      <div class="pvc-row">
        <div class="pvc-table">
          <div class="pvc-col">
            <div class="pvc-head">H</div>
            <div class="pvc-val">4</div>
          </div>
          <div class="pvc-col zero-col">
            <div class="pvc-head">T</div>
            <div class="pvc-val">0</div>
          </div>
          <div class="pvc-col">
            <div class="pvc-head">O</div>
            <div class="pvc-val">6</div>
          </div>
        </div>

        <div class="zero-badge">
          <span>←</span> 0 Tens Placeholder
        </div>
      </div>
    </div>

    
    <div class="num-card" id="card-ones">
      <div class="equation-row">
        <span class="term h-term">700</span>
        <span class="symbol">+</span>
        <span class="term t-term">80</span>
        <span class="symbol">+</span>
        <span class="term zero-highlight">0</span>
        <span class="symbol">=</span>
        <span class="result">780</span>
      </div>

      <div class="flow-arrow">▼</div>

      <div class="pvc-row">
        <div class="pvc-table">
          <div class="pvc-col">
            <div class="pvc-head">H</div>
            <div class="pvc-val">7</div>
          </div>
          <div class="pvc-col">
            <div class="pvc-head">T</div>
            <div class="pvc-val">8</div>
          </div>
          <div class="pvc-col zero-col">
            <div class="pvc-head">O</div>
            <div class="pvc-val">0</div>
          </div>
        </div>

        <div class="zero-badge">
          <span>←</span> 0 Ones Placeholder
        </div>
      </div>
    </div>
  </div>

  <script>
    function setMode(mode) {
      const buttons = document.querySelectorAll('.tab-btn');
      buttons.forEach(btn => btn.classList.remove('active'));

      const cardTens = document.getElementById('card-tens');
      const cardOnes = document.getElementById('card-ones');

      if (mode === 'all') {
        buttons[0].classList.add('active');
        cardTens.classList.remove('dimmed');
        cardOnes.classList.remove('dimmed');
      } else if (mode === 'tens') {
        buttons[1].classList.add('active');
        cardTens.classList.remove('dimmed');
        cardOnes.classList.add('dimmed');
      } else if (mode === 'ones') {
        buttons[2].classList.add('active');
        cardTens.classList.add('dimmed');
        cardOnes.classList.remove('dimmed');
      }
    }
  </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: #f8fafc;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
      padding: 16px;
      gap: 12px;
    }

    /* Top: Spoken Words Banner */
    .spoken-card {
      width: 100%;
      max-width: 480px;
      background: #ffffff;
      border: 2px solid #e2e8f0;
      border-radius: 12px;
      padding: 10px 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      font-size: 17px;
      font-weight: 700;
      color: #0f172a;
      box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    }

    .spoken-icon {
      font-size: 20px;
    }

    .quote {
      color: #2563eb;
      font-size: 18px;
    }

    /* Comparison Area */
    .comparison-grid {
      width: 100%;
      max-width: 480px;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    /* Incorrect Card */
    .attempt-card {
      position: relative;
      border-radius: 14px;
      padding: 12px 16px;
      display: flex;
      flex-direction: column;
      gap: 8px;
      transition: transform 0.2s ease, box-shadow 0.2s ease;
    }

    .attempt-card.error {
      background: #fef2f2;
      border: 2px solid #fca5a5;
    }

    .attempt-card.correct {
      background: #f0fdf4;
      border: 2px solid #86efac;
    }

    .card-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      font-size: 13px;
      font-weight: 700;
      letter-spacing: 0.5px;
      text-transform: uppercase;
    }

    .status-tag {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      padding: 3px 8px;
      border-radius: 6px;
      font-size: 12px;
      font-weight: 800;
    }

    .status-tag.error {
      background: #fee2e2;
      color: #b91c1c;
    }

    .status-tag.correct {
      background: #dcfce7;
      color: #15803d;
    }

    /* Visual Content */
    .display-row {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 8px;
      flex-wrap: wrap;
    }

    .digits-group {
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .struck-number {
      font-size: 28px;
      font-weight: 800;
      letter-spacing: 4px;
      color: #dc2626;
      position: relative;
      padding: 2px 6px;
      background: #ffffff;
      border: 1.5px solid #fecaca;
      border-radius: 8px;
      text-decoration: line-through;
      text-decoration-thickness: 3px;
      text-decoration-color: #dc2626;
    }

    .place-slots {
      display: flex;
      gap: 6px;
    }

    .slot {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      width: 44px;
      height: 48px;
      background: #ffffff;
      border: 2px solid #86efac;
      border-radius: 8px;
      box-shadow: 0 1px 2px rgba(0,0,0,0.04);
      cursor: pointer;
      user-select: none;
      transition: background 0.15s ease, border-color 0.15s ease;
    }

    .slot.active, .slot:hover {
      background: #dcfce7;
      border-color: #16a34a;
    }

    .slot-label {
      font-size: 10px;
      font-weight: 800;
      color: #15803d;
      line-height: 1;
    }

    .slot-val {
      font-size: 22px;
      font-weight: 800;
      color: #0f172a;
      line-height: 1.2;
    }

    .slot.zero-tens {
      border-color: #3b82f6;
      background: #eff6ff;
    }

    .slot.zero-tens .slot-label {
      color: #2563eb;
    }

    .result-badge {
      font-size: 22px;
      font-weight: 900;
      color: #15803d;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .reason-text {
      font-size: 13px;
      font-weight: 600;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .reason-text.error {
      color: #b91c1c;
    }

    .reason-text.correct {
      color: #166534;
    }

    .tens-callout {
      background: #ffffff;
      border-radius: 6px;
      padding: 4px 8px;
      font-size: 12px;
      font-weight: 600;
      color: #1e40af;
      border: 1px dashed #93c5fd;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }
  </style>
</head>
<body>

  
  <div class="spoken-card">
    <span class="spoken-icon">🗣️</span>
    <span>Spoken words: <span class="quote">“Three hundred six”</span></span>
  </div>

  <div class="comparison-grid">

    
    <div class="attempt-card error">
      <div class="card-header">
        <span style="color:#991b1b;">Incorrect Attempt</span>
        <span class="status-tag error">✕ 4 Digits</span>
      </div>
      <div class="display-row">
        <div class="struck-number">3006</div>
        <div class="reason-text error">
          <span>❌ 4 digits = Thousands (Too long!)</span>
        </div>
      </div>
    </div>

    
    <div class="attempt-card correct">
      <div class="card-header">
        <span style="color:#166534;">Correct Place Value</span>
        <span class="status-tag correct">✓ 3 Digits</span>
      </div>
      <div class="display-row">
        <div class="place-slots">
          <div class="slot" title="Hundreds place">
            <span class="slot-label">H</span>
            <span class="slot-val">3</span>
          </div>
          <div class="slot zero-tens" title="Zero tens placeholder">
            <span class="slot-label">T</span>
            <span class="slot-val">0</span>
          </div>
          <div class="slot" title="Ones place">
            <span class="slot-label">O</span>
            <span class="slot-val">6</span>
          </div>
        </div>
        <div class="result-badge">
          <span>=</span>
          <span>306</span>
          <span style="font-size: 20px;">✓</span>
        </div>
      </div>
      <div class="display-row" style="margin-top: 2px;">
        <div class="tens-callout">
          <span>ℹ️ <strong>0</strong> holds the empty tens place</span>
        </div>
      </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">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, sans-serif;
      color: #1e2945;
      background: transparent;
      padding: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100vh;
      user-select: none;
    }

    /* Preset selector */
    .controls {
      display: flex;
      gap: 8px;
      margin-bottom: 10px;
      width: 100%;
      max-width: 360px;
      justify-content: center;
    }
    .pill-btn {
      flex: 1;
      padding: 7px 10px;
      border: 1px solid #cbd5e1;
      background: #ffffff;
      color: #1e2945;
      font-size: 14px;
      font-weight: 700;
      border-radius: 20px;
      cursor: pointer;
      box-shadow: 0 1px 2px rgba(0,0,0,0.05);
      transition: background-color 0.15s, border-color 0.15s, color 0.15s;
    }
    .pill-btn:hover {
      background: #f0f9ff;
      border-color: #0284c7;
    }
    .pill-btn.active {
      background: #0284c7;
      border-color: #0369a1;
      color: #ffffff;
    }

    /* House structure */
    .house {
      width: 100%;
      max-width: 360px;
      display: flex;
      flex-direction: column;
      align-items: center;
    }

    /* Roof */
    .roof {
      width: 100%;
      height: 28px;
      background: #38bdf8;
      clip-path: polygon(50% 0%, 100% 100%, 0% 100%);
      border-radius: 4px 4px 0 0;
    }

    /* Rooms Container */
    .rooms {
      width: 100%;
      display: grid;
      grid-template-columns: 1fr 1fr 1fr;
      background: #f0f7ff;
      border: 2px solid #bae6fd;
      border-top: none;
      border-radius: 0 0 12px 12px;
    }

    .room {
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 8px 3px;
      border-right: 1px dashed #7dd3fc;
      min-width: 0;
    }
    .room:last-child {
      border-right: none;
    }

    /* Room Header */
    .room-label {
      font-size: 11px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.3px;
      color: #0369a1;
      margin-bottom: 4px;
      text-align: center;
      white-space: nowrap;
    }
    .digit-box {
      width: 36px;
      height: 38px;
      background: #ffffff;
      border: 2px solid #38bdf8;
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 22px;
      font-weight: 800;
      color: #1e2945;
      box-shadow: 0 2px 4px rgba(0,0,0,0.04);
      margin-bottom: 6px;
    }
    .digit-box.zero {
      border-color: #f59e0b;
      color: #b45309;
      background: #fffbeb;
    }

    /* Block Display Area */
    .block-area {
      width: 100%;
      height: 185px;
      background: #ffffff;
      border: 1px solid #e0f2fe;
      border-radius: 6px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      padding: 4px 2px;
      position: relative;
      overflow: hidden;
    }

    .empty-state {
      font-size: 20px;
      font-weight: 800;
      color: #334155;
      background: #f1f5f9;
      width: 36px;
      height: 36px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      border: 2px dashed #94a3b8;
    }

    /* SVG Blocks styling */
    svg.flat-100 {
      width: 32px;
      height: 32px;
      flex-shrink: 0;
    }
    svg.rod-10 {
      width: 8px;
      height: 64px;
      flex-shrink: 0;
    }
    svg.unit-1 {
      width: 12px;
      height: 12px;
      flex-shrink: 0;
    }

    .grid-wrap {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      justify-content: center;
      align-content: center;
      gap: 3px;
      width: 100%;
      height: 100%;
      padding: 2px;
    }

    /* Stepper buttons under rooms */
    .step-btn-group {
      display: flex;
      gap: 4px;
      margin-top: 6px;
    }
    .mini-btn {
      width: 26px;
      height: 26px;
      border: 1px solid #cbd5e1;
      background: #f8fafc;
      border-radius: 6px;
      font-size: 15px;
      font-weight: 700;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      color: #1e2945;
      line-height: 1;
      transition: background-color 0.15s, border-color 0.15s;
    }
    .mini-btn:hover {
      background: #e2e8f0;
      border-color: #94a3b8;
    }
    .mini-btn:active {
      background: #cbd5e1;
    }

    @media (min-width: 400px) {
      .room-label {
        font-size: 12px;
      }
      svg.flat-100 {
        width: 34px;
        height: 34px;
      }
    }
  </style>
</head>
<body>

  
  <div class="controls">
    <button class="pill-btn active" onclick="setNumber(5, 0, 8, this)">508</button>
    <button class="pill-btn" onclick="setNumber(0, 5, 8, this)">58</button>
    <button class="pill-btn" onclick="setNumber(3, 4, 2, this)">342</button>
  </div>

  
  <div class="house">
    <div class="roof"></div>
    <div class="rooms">
      
      
      <div class="room">
        <div class="room-label">Hundreds (H)</div>
        <div class="digit-box" id="h-digit">5</div>
        <div class="block-area" id="h-blocks"></div>
        <div class="step-btn-group">
          <button class="mini-btn" aria-label="Decrease Hundreds" onclick="adjust('h', -1)">−</button>
          <button class="mini-btn" aria-label="Increase Hundreds" onclick="adjust('h', 1)">+</button>
        </div>
      </div>

      
      <div class="room">
        <div class="room-label">Tens (T)</div>
        <div class="digit-box" id="t-digit">0</div>
        <div class="block-area" id="t-blocks"></div>
        <div class="step-btn-group">
          <button class="mini-btn" aria-label="Decrease Tens" onclick="adjust('t', -1)">−</button>
          <button class="mini-btn" aria-label="Increase Tens" onclick="adjust('t', 1)">+</button>
        </div>
      </div>

      
      <div class="room">
        <div class="room-label">Ones (O)</div>
        <div class="digit-box" id="o-digit">8</div>
        <div class="block-area" id="o-blocks"></div>
        <div class="step-btn-group">
          <button class="mini-btn" aria-label="Decrease Ones" onclick="adjust('o', -1)">−</button>
          <button class="mini-btn" aria-label="Increase Ones" onclick="adjust('o', 1)">+</button>
        </div>
      </div>

    </div>
  </div>

  <script>
    let valH = 5, valT = 0, valO = 8;

    function createFlatSvg() {
      return `<svg class="flat-100" viewBox="0 0 100 100">
        <rect x="1" y="1" width="98" height="98" fill="#fbbf24" stroke="#d97706" stroke-width="2" rx="3"/>
        <path d="M10 0v100M20 0v100M30 0v100M40 0v100M50 0v100M60 0v100M70 0v100M80 0v100M90 0v100M0 10h100M0 20h100M0 30h100M0 40h100M0 50h100M0 60h100M0 70h100M0 80h100M0 90h100" stroke="#d97706" stroke-width="1" opacity="0.6"/>
      </svg>`;
    }

    function createRodSvg() {
      return `<svg class="rod-10" viewBox="0 0 10 100">
        <rect x="0.5" y="0.5" width="9" height="99" fill="#fbbf24" stroke="#d97706" stroke-width="1.5" rx="2"/>
        <path d="M0 10h10M0 20h10M0 30h10M0 40h10M0 50h10M0 60h10M0 70h10M0 80h10M0 90h10" stroke="#d97706" stroke-width="1" opacity="0.6"/>
      </svg>`;
    }

    function createUnitSvg() {
      return `<svg class="unit-1" viewBox="0 0 10 10">
        <rect x="1" y="1" width="8" height="8" fill="#fbbf24" stroke="#d97706" stroke-width="1.5" rx="1"/>
      </svg>`;
    }

    function render() {
      // Digits
      const hBox = document.getElementById('h-digit');
      const tBox = document.getElementById('t-digit');
      const oBox = document.getElementById('o-digit');

      hBox.textContent = valH;
      tBox.textContent = valT;
      oBox.textContent = valO;

      hBox.className = 'digit-box' + (valH === 0 ? ' zero' : '');
      tBox.className = 'digit-box' + (valT === 0 ? ' zero' : '');
      oBox.className = 'digit-box' + (valO === 0 ? ' zero' : '');

      // Blocks
      const hArea = document.getElementById('h-blocks');
      const tArea = document.getElementById('t-blocks');
      const oArea = document.getElementById('o-blocks');

      hArea.innerHTML = valH === 0 ? '<div class="empty-state">0</div>' : `<div class="grid-wrap">${createFlatSvg().repeat(valH)}</div>`;
      tArea.innerHTML = valT === 0 ? '<div class="empty-state">0</div>' : `<div class="grid-wrap">${createRodSvg().repeat(valT)}</div>`;
      oArea.innerHTML = valO === 0 ? '<div class="empty-state">0</div>' : `<div class="grid-wrap">${createUnitSvg().repeat(valO)}</div>`;
    }

    function setNumber(h, t, o, btn) {
      valH = h; valT = t; valO = o;
      document.querySelectorAll('.pill-btn').forEach(b => b.classList.remove('active'));
      if (btn) btn.classList.add('active');
      render();
    }

    function adjust(place, delta) {
      document.querySelectorAll('.pill-btn').forEach(b => b.classList.remove('active'));
      if (place === 'h') valH = Math.max(0, Math.min(9, valH + delta));
      if (place === 't') valT = Math.max(0, Math.min(9, valT + delta));
      if (place === 'o') valO = Math.max(0, Math.min(9, valO + delta));
      render();
    }

    render();
  </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">
  <title>Place Value Placeholder 0</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: system-ui, -apple-system, sans-serif;
      color: #1e2945;
      background: transparent;
      padding: 10px;
      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: 440px) {
      .grid {
        grid-template-columns: 1fr;
        gap: 10px;
      }
    }
    .panel-correct {
      background: #f0fdf4;
      border: 2px solid #86efac;
      border-radius: 12px;
      padding: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 8px;
    }
    .panel-wrong {
      background: #fef2f2;
      border: 2px solid #fca5a5;
      border-radius: 12px;
      padding: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 8px;
    }
    .badge-correct {
      background: #22c55e;
      color: white;
      font-size: 13px;
      font-weight: 700;
      padding: 2px 10px;
      border-radius: 20px;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }
    .badge-wrong {
      background: #ef4444;
      color: white;
      font-size: 13px;
      font-weight: 700;
      padding: 2px 10px;
      border-radius: 20px;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }
    .blocks-row {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      min-height: 72px;
      width: 100%;
      background: rgba(255, 255, 255, 0.7);
      border-radius: 8px;
      padding: 6px;
    }
    .flats-group {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 3px;
    }
    .flat {
      width: 28px;
      height: 28px;
      background: #bae6fd;
      border: 1px solid #0284c7;
      border-radius: 2px;
      position: relative;
    }
    .flat::after {
      content: "100";
      position: absolute;
      inset: 0;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 9px;
      font-weight: 700;
      color: #0369a1;
    }
    .empty-rod {
      width: 18px;
      height: 48px;
      border: 1.5px dashed #cbd5e1;
      border-radius: 3px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 11px;
      color: #94a3b8;
      font-weight: 700;
    }
    .units-group {
      display: flex;
      flex-direction: column;
      gap: 2px;
    }
    .unit {
      width: 8px;
      height: 8px;
      background: #fde047;
      border: 1px solid #ca8a04;
      border-radius: 1.5px;
    }
    .pv-table {
      display: grid;
      border: 1.5px solid #cbd5e1;
      border-radius: 8px;
      overflow: hidden;
      background: white;
      text-align: center;
      width: 100%;
      max-width: 220px;
    }
    .pv-3 {
      grid-template-columns: 1fr 1fr 1fr;
    }
    .pv-2 {
      grid-template-columns: 1fr 1fr;
    }
    .pv-th {
      font-size: 11px;
      font-weight: 700;
      padding: 4px 2px;
      background: #f1f5f9;
      color: #475569;
      border-bottom: 1px solid #cbd5e1;
      border-right: 1px solid #cbd5e1;
    }
    .pv-th:last-child {
      border-right: none;
    }
    .pv-td {
      font-size: 20px;
      font-weight: 800;
      padding: 6px 2px;
      border-right: 1px solid #cbd5e1;
    }
    .pv-td:last-child {
      border-right: none;
    }
    .c-hundreds { color: #0284c7; }
    .c-zero { color: #16a34a; background: #dcfce7; }
    .c-ones { color: #ca8a04; }
    .c-tens-wrong { color: #dc2626; background: #fee2e2; }
    
    .total-display {
      font-size: 26px;
      font-weight: 900;
      letter-spacing: 0.5px;
    }
    .total-correct {
      color: #15803d;
    }
    .total-wrong {
      color: #b91c1c;
      text-decoration: line-through 3px #ef4444;
    }
    .tag-note {
      font-size: 12px;
      font-weight: 600;
      text-align: center;
    }
    .tag-correct { color: #166534; }
    .tag-wrong { color: #991b1b; }
  </style>
</head>
<body>
  <div class="grid">
    
    <div class="panel-correct">
      <div class="badge-correct">✓ Keep 0</div>
      
      <div class="blocks-row">
        <div class="flats-group" title="4 Hundreds (400)">
          <div class="flat"></div>
          <div class="flat"></div>
          <div class="flat"></div>
          <div class="flat"></div>
        </div>
        <div class="empty-rod" title="0 Tens">0</div>
        <div class="units-group" title="5 Ones">
          <div class="unit"></div>
          <div class="unit"></div>
          <div class="unit"></div>
          <div class="unit"></div>
          <div class="unit"></div>
        </div>
      </div>

      <div class="pv-table pv-3">
        <div class="pv-th">Hundreds</div>
        <div class="pv-th">Tens</div>
        <div class="pv-th">Ones</div>
        <div class="pv-td c-hundreds">4</div>
        <div class="pv-td c-zero">0</div>
        <div class="pv-td c-ones">5</div>
      </div>

      <div class="total-display total-correct">405</div>
      <div class="tag-note tag-correct">4 Hundreds + 5 Ones</div>
    </div>

    
    <div class="panel-wrong">
      <div class="badge-wrong">✕ Skip 0</div>

      <div class="blocks-row" style="opacity: 0.75;">
        <div style="font-size: 28px;">⚠️</div>
      </div>

      <div class="pv-table pv-2">
        <div class="pv-th">Tens</div>
        <div class="pv-th">Ones</div>
        <div class="pv-td c-tens-wrong">4</div>
        <div class="pv-td c-ones">5</div>
      </div>

      <div class="total-display total-wrong">45</div>
      <div class="tag-note tag-wrong">4 Tens + 5 Ones</div>
    </div>
  </div>
</body>
</html>

认识计数单位“十”与“百”

100以内数的组成与数位表

一个一个和十个十个地数到1000

认识计数单位“千”与1000的直观表征

1000以内数的读法与“0”的读法规则

1000以内数的写法与数位表应用

1000以内数的组成与数级分解

math

1000以内数的认识与读写

Building Three-Digit Numbers With Base-Ten Blocks

Introducing the Thousands Place

Composing Numbers to 1,200 Using Base-Ten Models

Decomposing Three-Digit Numbers in Multiple Ways

Decomposing Numbers to 1,200 in Multiple Ways

Writing Three-Digit Numbers from Models

Using Place Value Charts for Numbers to 1,200

Regrouping Tens Into Hundreds and Hundreds Into Thousands

Building Numbers to 1,200 With Place Value

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

Conteo, representación y patrones hasta 20

What Is Place Value? Understanding Digits in Numbers

Building Two-Digit Numbers With Base-Ten Blocks

Reading and Writing Two-Digit Numbers

Reading Three-Digit Number Names

Reading and Writing Numbers to 1,000

Representing Numbers to 1,000

Understanding Hundreds, Tens, and Ones

Reading and Writing Numbers Up to 1,200

Word Form of Numbers Up to 1,200

Expanded Form of Three-Digit Numbers

Converting Between Standard, Word, and Expanded Forms

Representing Numbers to 1,200

Wartość cyfry – jedności i dziesiątki

Wartość cyfry – setki i tysiące

Zapisywanie liczb cyframi i słownie

Poprzednik i następnik liczby

Porównywanie liczb do 10 000

Porządkowanie liczb rosnąco i malejąco

Liczby na osi liczbowej

Zapis i porządkowanie liczb do 10 000

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

Counting Within 1,000 by Ones

Counting Forward Across Decade Barriers Within 1,000

Counting Forward Across Century Barriers to 1,000

Counting Backward by Ones Within 500

Counting Backward by Ones Within 1,000

Counting Backward Across Decade and Century Barriers to 1,000

Identifying Numbers One More and One Less Within 1,000

Locating Three-Digit Numbers on Number Lines to 1,000

Counting to 1,000: Forward and Backward

Counting Tens and Ones to Find the Total

Identifying Tens and Ones in Two-Digit Numbers

Partitioning Two-Digit Numbers into Tens and Ones

Building Numbers With Different Tens and Ones Combinations

Representing Numbers to 100 on a Hundred Square

Locating Numbers on a 0 to 100 Number Line

Place Value and Representing Numbers to 100

Comprendre qu'une dizaine vaut 10 unités

Calculer le nombre de dizaines dans plusieurs centaines

Convertir des centaines en unités simples

Convertir des centaines en dizaines et unités

Déterminer le nombre total de dizaines dans un nombre à trois chiffres

Déterminer le nombre total d'unités dans un nombre à trois chiffres

Résoudre des énigmes de conversion entre unités, dizaines et centaines

Comprendre que 10 centaines forment mille

Relations entre unités, dizaines et centaines au CE1

认识计数单位“万”及10000的概念

万以内数位顺序表的建立与认识

万以内不含0的四位数的读写

万以内含0的数的读法与写法难点突破

万以内数的组成与数值分析

万以内数的认识与读写

Comparing Numbers Using Place Value

Comparing Three-Digit Numbers With >, <, and =

Locating Three-Digit Numbers on Open Number Lines

Ordering Three-Digit Numbers

Comparing and Ordering Numbers to 1,000

Comparing Numbers to 1,200 With Symbols

Comparing Numbers to 1,200 Using Comparative Language

Ordering Three-Digit Numbers From Smallest to Largest

Ordering Numbers Up to 1,200

Naming Whole Numbers at Points on Number Lines

Comparing, Ordering, and Locating Numbers to 1,200

Compter de 100 en 100 jusqu'à 10 000

Compter de 1 000 en 1 000 jusqu'à 10 000

Lire à voix haute les nombres à 4 chiffres sans zéro intercalaire

Lire à voix haute les nombres avec des zéros intercalaires

Écrire en chiffres un nombre dicté jusqu'à 10 000

Écrire les nombres en lettres jusqu'à 10 000 et traits d'union

Trouver le nombre précédent et le nombre suivant jusqu'à 10 000

Compter à rebours à partir d'un nombre à 4 chiffres

Franchir les dizaines, centaines et milliers dans la suite écrite

La suite des nombres jusqu'à 10 000

La suite orale des centaines entières : cent, deux cents, trois cents...

Lire les nombres à trois chiffres sans zéro intercalaire

Lire les nombres à trois chiffres avec un zéro aux unités ou aux dizaines

Écrire en chiffres les nombres entendus jusqu'à 1 000

Écrire en lettres les nombres jusqu'à 1 000 et règle des tirets

Franchir les dizaines et les centaines dans la suite numérique

Compter de 10 en 10 et de 100 en 100 jusqu'à 1 000

Trouver le nombre précédent et le suivant d'un nombre à trois chiffres

Compléter des suites numériques à pas constant jusqu'à 1 000

La suite orale et écrite des nombres jusqu'à 1 000

Lire et écrire les nombres de 100 à 999 en chiffres

Écrire les nombres de 100 à 999 en lettres

Lire et écrire les milliers piles en chiffres et en lettres

Lire les nombres à 4 chiffres avec l'espace des mille

Écrire les nombres à 4 chiffres en chiffres

Écrire les nombres jusqu'à 10 000 en lettres

Compter de 10 en 10 et de 100 en 100 jusqu'à 10 000

Franchir les dizaines et centaines en comptant

Trouver le nombre précédent et suivant jusqu'à 10 000

Compléter des suites numériques croissantes et décroissantes

La suite orale et écrite des nombres jusqu'à 10 000

Deciding If There Are Enough Items for Everyone

Identifying When There Are Not Enough Items

Recognizing When There Are Extra or Too Many Items

Matching Supplies to Activities Using Comparative Words

Adjusting a Set So There Is Just Enough

Quantities for a Purpose: Enough and Not Enough

Reading and Writing Numbers to 100 in Words

Comparing Two-Digit Numbers Using Tens and Ones

Comparing Numbers Using <, >, and =

Ordering Sets of Two-Digit Numbers

Solving Place Value Riddles and Puzzles

Reading, Comparing, and Ordering Numbers to 100

认识传统算盘的结构与梁珠定位

用算盘表示1到9及一颗上珠代表5的规则

用算盘表示百以内和千以内的数

用算盘表示万以内数与空档记0

数轴（数线）上万以内数的直观对应

生活中的万以内大数调查与表述

算盘记数与大数的直观表达

Estimating Small Quantities (1 to 5)

Using 5 as a Benchmark to Estimate

Using 10 as a Benchmark on a Ten-Frame

Estimating Quantities Up to 10 with Containers

Estimating and Then Counting to Check

Comparing Estimates: More or Less Than 20?

Estimating Quantities with Benchmarks

Lire et écrire les nombres de 100 à 199

Lire et écrire les nombres de 200 à 599

Lire et écrire les nombres de 600 à 1 000

Écrire les nombres en lettres avec les tirets et accords

Trouver le nombre précédent et le nombre suivant jusqu'à 1 000

La suite écrite et orale des nombres jusqu'à 1 000

Plotting Numbers on a Number Line

Finding Positions of Numbers to 1,200 on Number Lines

Naming the Number at a Specific Point on a Number Line

Counting Forward and Backward on Number Lines to 1,200

Number Lines to 1,200

Writing Three-Digit Numbers in Words

Writing Three-Digit Numbers in Expanded Form

Translating Between Expanded Form and Standard Numerals

Locating Numbers on Structured Number Lines to 1,000

Locating Numbers on Open Number Lines to 1,000

Understanding Roman Numerals from I to XII

Writing and Converting Clock Faces with Roman Numerals

Number Representations: Numerals, Words, Expanded Form, and Roman Numerals

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

认识关系符号“>”、“<”、“=”的数学含义

位数不同的万以内数的大小比较

位数相同的三位数大小比较

位数相同的四位数大小比较

多个万以内数的由小到大或由大到小排序

万以内数的大小比较与排序

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

Comparación y orden de números naturales

OGM.3.NBT.2

Aligned learning resources

Related diagrams