Advanced

Tutor model

i62 💰:9.4

i52 💰:7.9

🏆 i67 💰:62.5

i70 💰:125.0

i68 💰:125.0

🏆 i66 💰:75.0

i65 💰:125.0

i63 💰:62.5

i61 💰:75.0

i60 💰:9.4

i60 💰:37.5

i58 💰:62.5

i57 💰:22.5

i57 💰:37.5

i56 💰:45.0

⚡ i55 💰:11.25

i55 💰:37.5

i54 💰:62.5

i52 💰:35.0

i51 💰:37.5

i49 💰:15.0

i49 💰:62.5

i48 💰:11.3

i47 💰:7.5

i44 💰:25.0

i43 💰:37.5

i42 💰:187.5

i40 💰:5.0

i39 💰:100.0

i38 💰:37.5

i37 💰:11.0

i36 💰:187.5

i34 💰:12.5

i33 💰:37.5

i30 💰:1.0

i29 💰:1.5

i28 💰:150.0

i23 💰:20.0

i20 💰:4.0

i18 💰:1.0

i16 💰:25.0

i13 💰:1.5

Keep session private

What would you like to learn?

Override for the tutor's lesson content generation calls. Auto uses the system default (Claude Sonnet 5 for lesson text, Opus 5 for diagrams).

Lesson generation model

System default

i58 💰:18.8

i31 💰:11.0

i25 💰:31.3

Tutoring abilities

Imagine holding a tiny paperclip in one hand and a big bag of sugar in the other.

They both have weight, but we use two different units to measure them: **grams** and **kilograms**.

<!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: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
      user-select: none;
      -webkit-user-select: none;
    }

    body {
      background: #f8f9fa;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
      padding: 12px;
    }

    .main-wrap {
      width: 100%;
      max-width: 520px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 14px;
    }

    /* Preset Tabs */
    .presets {
      display: flex;
      gap: 8px;
      width: 100%;
      justify-content: center;
      flex-wrap: wrap;
    }

    .preset-btn {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 20px;
      padding: 6px 14px;
      font-size: 14px;
      font-weight: 600;
      color: #475569;
      cursor: pointer;
      box-shadow: 0 1px 2px rgba(0,0,0,0.04);
      transition: background-color 0.2s, color 0.2s, border-color 0.2s;
    }

    .preset-btn.active {
      background: #22b7ff;
      color: #ffffff;
      border-color: #22b7ff;
      box-shadow: 0 2px 6px rgba(34, 183, 255, 0.35);
    }

    /* Visual Conversion Bridge */
    .converter-row {
      display: grid;
      grid-template-columns: 1fr auto 1fr;
      align-items: center;
      gap: 10px;
      width: 100%;
    }

    .unit-card {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 16px 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      box-shadow: 0 2px 6px rgba(0, 0, 0, 0.04);
      min-height: 125px;
      justify-content: center;
    }

    .unit-icon {
      font-size: 26px;
      margin-bottom: 4px;
    }

    .unit-val {
      font-size: 22px;
      font-weight: 700;
      color: #1e2945;
      line-height: 1.2;
    }

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

    /* Operation Bridge */
    .bridge {
      display: flex;
      flex-direction: column;
      gap: 10px;
      align-items: center;
      padding: 0 4px;
    }

    .op-pill {
      display: flex;
      align-items: center;
      gap: 4px;
      padding: 5px 10px;
      border-radius: 14px;
      font-size: 13px;
      font-weight: 700;
      white-space: nowrap;
    }

    .op-mult {
      background: #eff6ff;
      color: #0284c7;
      border: 1px solid #bae6fd;
    }

    .op-div {
      background: #f0fdf4;
      color: #16a34a;
      border: 1px solid #bbf7d0;
    }

    .op-arrow {
      font-size: 11px;
    }

    /* Equality Display */
    .equality-bar {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 10px 18px;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      width: 100%;
      font-size: 19px;
      font-weight: 700;
      box-shadow: 0 2px 6px rgba(0, 0, 0, 0.04);
    }

    .eq-kg {
      color: #0284c7;
    }

    .eq-eq {
      color: #94a3b8;
    }

    .eq-g {
      color: #16a34a;
    }

    /* Interactive Slider */
    .slider-wrap {
      width: 100%;
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 12px 16px;
      display: flex;
      flex-direction: column;
      gap: 8px;
      box-shadow: 0 2px 6px rgba(0, 0, 0, 0.04);
    }

    .slider-labels {
      display: flex;
      justify-content: space-between;
      font-size: 12px;
      font-weight: 600;
      color: #94a3b8;
    }

    input[type="range"] {
      -webkit-appearance: none;
      appearance: none;
      width: 100%;
      height: 6px;
      background: #e2e8f0;
      border-radius: 3px;
      outline: none;
    }

    input[type="range"]::-webkit-slider-thumb {
      -webkit-appearance: none;
      width: 22px;
      height: 22px;
      border-radius: 50%;
      background: #22b7ff;
      cursor: pointer;
      box-shadow: 0 2px 5px rgba(34, 183, 255, 0.4);
      border: 2px solid #ffffff;
    }

    input[type="range"]::-moz-range-thumb {
      width: 22px;
      height: 22px;
      border-radius: 50%;
      background: #22b7ff;
      cursor: pointer;
      box-shadow: 0 2px 5px rgba(34, 183, 255, 0.4);
      border: 2px solid #ffffff;
    }
  </style>
</head>
<body>
  <div class="main-wrap">
    
    <div class="presets">
      <button class="preset-btn" data-kg="0.5">0.5 kg</button>
      <button class="preset-btn active" data-kg="1">1 kg</button>
      <button class="preset-btn" data-kg="2">2 kg</button>
      <button class="preset-btn" data-kg="3">3 kg</button>
      <button class="preset-btn" data-kg="5">5 kg</button>
    </div>

    
    <div class="converter-row">
      
      <div class="unit-card">
        <div class="unit-icon" id="kgIcon">🎒</div>
        <div class="unit-val" id="kgVal">1 kg</div>
        <div class="unit-name">Kilograms</div>
      </div>

      
      <div class="bridge">
        <div class="op-pill op-mult">
          <span>× 1000</span>
          <span class="op-arrow">➔</span>
        </div>
        <div class="op-pill op-div">
          <span class="op-arrow">⬅</span>
          <span>÷ 1000</span>
        </div>
      </div>

      
      <div class="unit-card">
        <div class="unit-icon" id="gIcon">📎</div>
        <div class="unit-val" id="gVal">1000 g</div>
        <div class="unit-name">Grams</div>
      </div>
    </div>

    
    <div class="equality-bar">
      <span class="eq-kg" id="eqKg">1 kg</span>
      <span class="eq-eq">=</span>
      <span class="eq-g" id="eqG">1000 g</span>
    </div>

    
    <div class="slider-wrap">
      <input type="range" id="kgSlider" min="0.5" max="5" step="0.5" value="1">
      <div class="slider-labels">
        <span>0.5 kg</span>
        <span>2.5 kg</span>
        <span>5 kg</span>
      </div>
    </div>
  </div>

  <script>
    const slider = document.getElementById('kgSlider');
    const kgVal = document.getElementById('kgVal');
    const gVal = document.getElementById('gVal');
    const eqKg = document.getElementById('eqKg');
    const eqG = document.getElementById('eqG');
    const kgIcon = document.getElementById('kgIcon');
    const presetBtns = document.querySelectorAll('.preset-btn');

    const icons = {
      0.5: '🍎',
      1: '🎒',
      2: '🍈',
      3: '🍉',
      4: '📦',
      5: '🏋️'
    };

    function update(val) {
      const kg = parseFloat(val);
      const g = Math.round(kg * 1000);

      kgVal.textContent = kg + ' kg';
      gVal.textContent = g.toLocaleString() + ' g';

      eqKg.textContent = kg + ' kg';
      eqG.textContent = g.toLocaleString() + ' g';

      slider.value = kg;
      kgIcon.textContent = icons[kg] || '📦';

      presetBtns.forEach(btn => {
        if (parseFloat(btn.dataset.kg) === kg) {
          btn.classList.add('active');
        } else {
          btn.classList.remove('active');
        }
      });
    }

    slider.addEventListener('input', (e) => {
      update(e.target.value);
    });

    presetBtns.forEach(btn => {
      btn.addEventListener('click', () => {
        update(btn.dataset.kg);
      });
    });
  </script>
</body>
</html>

A **gram** (written as **g**) measures super light things, while a **kilogram** (written as **kg**) measures heavier things.

The secret to swapping between them is the magic number **1,000**, because exactly 1,000 grams fit inside 1 kilogram.

How do we find out how many grams are in 3 whole kilograms of apples?

To change from big kilograms to small grams, we **multiply by 1,000**.

Because each kilogram has 1,000 grams inside, 3 kilograms gives us $3 \times 1,000 = 3,000\text{ g}$.

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<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: #f8f9fa; color: #1e2945; display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 12px; min-height: 100%; }

  .container { width: 100%; max-width: 480px; display: flex; flex-direction: column; gap: 14px; }

  /* Conversion Rule Banner */
  .rule-bar {
    background: #ffffff;
    border-radius: 12px;
    padding: 10px 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
  }
  .unit-tag { font-weight: 700; font-size: 16px; color: #1e2945; }
  .rule-arrows { display: flex; flex-direction: column; gap: 4px; align-items: center; flex: 1; padding: 0 12px; }
  .arrow-pill {
    font-size: 12px;
    font-weight: 600;
    padding: 2px 8px;
    border-radius: 20px;
    display: flex;
    align-items: center;
    gap: 4px;
    transition: opacity 0.2s ease, transform 0.2s ease;
  }
  .arrow-mult { background: #ecfdf5; color: #059669; }
  .arrow-div { background: #eff6ff; color: #2563eb; }

  /* Balance / Comparison Area */
  .visual-card {
    background: #ffffff;
    border-radius: 12px;
    padding: 16px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
    display: flex;
    flex-direction: column;
    gap: 12px;
  }

  .scale-display {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    gap: 8px;
    text-align: center;
  }
  .value-box {
    background: #f8f9fa;
    border: 2px solid #e5e7eb;
    border-radius: 10px;
    padding: 10px 6px;
    transition: all 0.2s ease;
  }
  .value-box.active-kg { border-color: #10b981; background: #f0fdf4; }
  .value-box.active-g { border-color: #3b82f6; background: #eff6ff; }

  .val-num { font-size: 22px; font-weight: 800; line-height: 1.1; }
  .val-unit { font-size: 13px; font-weight: 600; color: #6b7280; }

  .equals-sign { font-size: 20px; font-weight: 700; color: #9ca3af; }

  /* Visual Blocks Stack */
  .blocks-area {
    min-height: 72px;
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    justify-content: center;
    align-items: center;
    background: #fdfdfd;
    border: 1px dashed #d1d5db;
    border-radius: 10px;
    padding: 8px;
  }
  .block-item {
    background: #10b981;
    color: #ffffff;
    font-size: 11px;
    font-weight: 700;
    padding: 6px 10px;
    border-radius: 6px;
    display: flex;
    align-items: center;
    gap: 4px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    transition: transform 0.2s ease, opacity 0.2s ease;
  }

  /* Formula display */
  .calc-pill {
    text-align: center;
    font-size: 14px;
    font-weight: 600;
    color: #374151;
    background: #f3f4f6;
    padding: 6px 12px;
    border-radius: 8px;
  }

  /* Preset Selector Buttons */
  .preset-row {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 6px;
  }
  .preset-btn {
    border: 1px solid #d1d5db;
    background: #ffffff;
    padding: 8px 0;
    border-radius: 8px;
    font-size: 13px;
    font-weight: 700;
    color: #4b5563;
    cursor: pointer;
    transition: all 0.15s ease;
  }
  .preset-btn:hover { background: #f9fafb; border-color: #9ca3af; }
  .preset-btn.active {
    background: #10b981;
    color: #ffffff;
    border-color: #10b981;
    box-shadow: 0 2px 6px rgba(16,185,129,0.3);
  }
</style>
</head>
<body>

<div class="container">
  
  <div class="rule-bar">
    <span class="unit-tag">kg</span>
    <div class="rule-arrows">
      <span class="arrow-pill arrow-mult">× 1,000 →</span>
      <span class="arrow-pill arrow-div">← ÷ 1,000</span>
    </div>
    <span class="unit-tag">g</span>
  </div>

  
  <div class="visual-card">
    <div class="scale-display">
      <div class="value-box active-kg">
        <div class="val-num" id="kgVal">1</div>
        <div class="val-unit">kg</div>
      </div>
      <div class="equals-sign">=</div>
      <div class="value-box active-g">
        <div class="val-num" id="gVal">1,000</div>
        <div class="val-unit">g</div>
      </div>
    </div>

    
    <div class="blocks-area" id="blocksArea"></div>

    
    <div class="calc-pill" id="calcText">1 × 1,000 = 1,000 g</div>
  </div>

  
  <div class="preset-row">
    <button class="preset-btn active" data-kg="1">1 kg</button>
    <button class="preset-btn" data-kg="2">2 kg</button>
    <button class="preset-btn" data-kg="3">3 kg</button>
    <button class="preset-btn" data-kg="4">4 kg</button>
    <button class="preset-btn" data-kg="5">5 kg</button>
  </div>
</div>

<script>
  const buttons = document.querySelectorAll('.preset-btn');
  const kgVal = document.getElementById('kgVal');
  const gVal = document.getElementById('gVal');
  const blocksArea = document.getElementById('blocksArea');
  const calcText = document.getElementById('calcText');

  function updateView(kg) {
    kgVal.textContent = kg;
    const g = kg * 1000;
    gVal.textContent = g.toLocaleString();
    calcText.textContent = `${kg} × 1,000 = ${g.toLocaleString()} g`;

    // Render 1000g blocks
    blocksArea.innerHTML = '';
    for (let i = 0; i < kg; i++) {
      const b = document.createElement('div');
      b.className = 'block-item';
      b.textContent = '📦 1,000 g';
      blocksArea.appendChild(b);
    }
  }

  buttons.forEach(btn => {
    btn.addEventListener('click', () => {
      buttons.forEach(b => b.classList.remove('active'));
      btn.classList.add('active');
      updateView(parseInt(btn.getAttribute('data-kg'), 10));
    });
  });

  // Initial render
  updateView(1);
</script>

</body>
</html>

What if a box of toys is marked as 5,000 grams — how many kilograms is that?

To go backward from grams to kilograms, we do the opposite: we **divide by 1,000**.

We group the grams into sets of 1,000, so $5,000 \div 1,000 = 5\text{ kg}$.

<!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>Converting Grams and Kilograms</title>
  <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.16.8/dist/katex.min.css">
  <script defer src="https://cdn.jsdelivr.net/npm/katex@0.16.8/dist/katex.min.js"></script>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
      -webkit-tap-highlight-color: transparent;
    }

    body {
      background: #f8f9fa;
      color: #1e2945;
      display: flex;
      justify-content: center;
      align-items: center;
      padding: 16px;
      min-height: 100vh;
    }

    .diagram {
      width: 100%;
      max-width: 580px;
      display: flex;
      flex-direction: column;
      gap: 16px;
      align-items: center;
    }

    .nav-bar {
      display: flex;
      gap: 8px;
      background: #eceff3;
      padding: 4px;
      border-radius: 12px;
      width: 100%;
      max-width: 380px;
    }

    .tab-btn {
      flex: 1;
      border: none;
      background: transparent;
      padding: 8px 12px;
      font-size: 14px;
      font-weight: 600;
      color: #6b7280;
      border-radius: 8px;
      cursor: pointer;
      transition: all 0.2s ease;
      text-align: center;
    }

    .tab-btn.active {
      background: #ffffff;
      color: #8b5cf6;
      box-shadow: 0 2px 6px rgba(0, 0, 0, 0.08);
    }

    .presets {
      display: flex;
      gap: 8px;
      justify-content: center;
      width: 100%;
    }

    .preset-btn {
      border: 1px solid #e5e7eb;
      background: #ffffff;
      padding: 6px 14px;
      border-radius: 20px;
      font-size: 14px;
      font-weight: 600;
      color: #4b5563;
      cursor: pointer;
      transition: all 0.2s ease;
    }

    .preset-btn.active {
      background: #8b5cf6;
      border-color: #8b5cf6;
      color: #ffffff;
    }

    .stage {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      background: #ffffff;
      border: 1px solid #e5e7eb;
      border-radius: 16px;
      padding: 20px 16px;
      gap: 12px;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.03);
    }

    .unit-box {
      flex: 1;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 10px;
      min-width: 100px;
    }

    .icon-display {
      height: 90px;
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
    }

    .weight-kettle {
      width: 68px;
      height: 68px;
      background: linear-gradient(135deg, #a78bfa, #8b5cf6);
      border-radius: 14px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: #ffffff;
      font-size: 26px;
      font-weight: 700;
      box-shadow: 0 4px 10px rgba(139, 92, 246, 0.25);
      position: relative;
    }

    .weight-kettle::before {
      content: "";
      position: absolute;
      top: -10px;
      width: 32px;
      height: 14px;
      border: 4px solid #8b5cf6;
      border-bottom: none;
      border-radius: 10px 10px 0 0;
    }

    .gram-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 6px;
      max-width: 120px;
    }

    .gram-block {
      background: #ede9fe;
      border: 1px solid #c4b5fd;
      border-radius: 6px;
      padding: 4px 6px;
      font-size: 11px;
      font-weight: 700;
      color: #6d28d9;
      text-align: center;
      display: flex;
      flex-direction: column;
      align-items: center;
      animation: popIn 0.3s ease;
    }

    @keyframes popIn {
      from { transform: scale(0.6); opacity: 0; }
      to { transform: scale(1); opacity: 1; }
    }

    .conversion-mid {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 6px;
      padding: 0 4px;
    }

    .op-badge {
      background: #f3f0ff;
      color: #7c3aed;
      border: 1px solid #ddd6fe;
      font-size: 15px;
      font-weight: 700;
      padding: 6px 14px;
      border-radius: 20px;
      white-space: nowrap;
    }

    .arrow-indicator {
      font-size: 22px;
      color: #8b5cf6;
      line-height: 1;
    }

    .math-bar {
      width: 100%;
      background: #ffffff;
      border: 1px solid #e5e7eb;
      border-radius: 12px;
      padding: 12px;
      display: flex;
      justify-content: center;
      align-items: center;
      min-height: 48px;
    }

    .math-target {
      font-size: 19px;
      color: #1e2945;
    }
  </style>
</head>
<body>

<div class="diagram">
  <div class="nav-bar">
    <button class="tab-btn active" id="btnKgToG">kg → g</button>
    <button class="tab-btn" id="btnGToKg">g → kg</button>
  </div>

  <div class="presets">
    <button class="preset-btn active" data-val="1">1</button>
    <button class="preset-btn" data-val="2">2</button>
    <button class="preset-btn" data-val="3">3</button>
    <button class="preset-btn" data-val="5">5</button>
  </div>

  <div class="stage">
    <div class="unit-box">
      <div class="icon-display">
        <div class="weight-kettle" id="kgWeightIcon">1</div>
      </div>
      <div id="kgLabel"></div>
    </div>

    <div class="conversion-mid">
      <div class="op-badge" id="opBadge">× 1,000</div>
      <div class="arrow-indicator" id="arrowIcon">→</div>
    </div>

    <div class="unit-box">
      <div class="icon-display">
        <div class="gram-grid" id="gramGrid"></div>
      </div>
      <div id="gLabel"></div>
    </div>
  </div>

  <div class="math-bar">
    <div class="math-target" id="equation"></div>
  </div>
</div>

<script>
  let mode = 'kgToG'; // 'kgToG' or 'gToKg'
  let currentVal = 1;

  function renderKatex(tex, el) {
    if (window.katex) {
      katex.render(tex, el, { throwOnError: false });
    } else {
      el.textContent = tex;
    }
  }

  function update() {
    const kgVal = currentVal;
    const gVal = currentVal * 1000;

    document.getElementById('kgWeightIcon').textContent = kgVal;

    const grid = document.getElementById('gramGrid');
    grid.innerHTML = '';
    for (let i = 0; i < currentVal; i++) {
      const block = document.createElement('div');
      block.className = 'gram-block';
      block.innerHTML = '<span>1k</span>';
      grid.appendChild(block);
    }

    const kgLabel = document.getElementById('kgLabel');
    const gLabel = document.getElementById('gLabel');
    const opBadge = document.getElementById('opBadge');
    const arrow = document.getElementById('arrowIcon');
    const eq = document.getElementById('equation');

    renderKatex(`${kgVal}\\text{ kg}`, kgLabel);
    renderKatex(`${gVal.toLocaleString()}\\text{ g}`, gLabel);

    if (mode === 'kgToG') {
      opBadge.textContent = '× 1,000';
      arrow.textContent = '→';
      renderKatex(`${kgVal}\\text{ kg} \\times 1{,}000 = ${gVal.toLocaleString()}\\text{ g}`, eq);
    } else {
      opBadge.textContent = '÷ 1,000';
      arrow.textContent = '←';
      renderKatex(`${gVal.toLocaleString()}\\text{ g} \\div 1{,}000 = ${kgVal}\\text{ kg}`, eq);
    }
  }

  document.getElementById('btnKgToG').onclick = () => {
    mode = 'kgToG';
    document.getElementById('btnKgToG').classList.add('active');
    document.getElementById('btnGToKg').classList.remove('active');
    update();
  };

  document.getElementById('btnGToKg').onclick = () => {
    mode = 'gToKg';
    document.getElementById('btnGToKg').classList.add('active');
    document.getElementById('btnKgToG').classList.remove('active');
    update();
  };

  document.querySelectorAll('.preset-btn').forEach(btn => {
    btn.onclick = () => {
      document.querySelectorAll('.preset-btn').forEach(b => b.classList.remove('active'));
      btn.classList.add('active');
      currentVal = parseInt(btn.dataset.val, 10);
      update();
    };
  });

  window.addEventListener('load', update);
  setTimeout(update, 200);
</script>

</body>
</html>

Watch out for a common trick: $2\text{ kg}$ is not smaller than $200\text{ g}$ just because the number $2$ looks tiny!

Always look at the unit: $2\text{ kg}$ is really $2,000\text{ g}$, which is way heavier than $200\text{ g}$.

Whenever you convert, just ask: am I packing grams into big kilograms, or unpacking kilograms into thousands of grams?

math

Converting Between Grams and Kilograms. Convert between grams (g) and kilograms (kg) using multiplication and division by 1,000.

Converting Metric Units of Mass: Grams and Kilograms (Second Level / KS2)

Converting Units of Mass: Grams and Kilograms

Convert Metric Units of Mass: Grams and Kilograms

Although labeled with an Early Level designator in legacy prompt tags, Curriculum for Excellence standard MNU 2-11b mathematically targets Second Level (Primary 5–7, ages 9–11) where multiplying and dividing decimals and integers by $1,000$ is taught. The core pedagogical approach uses concrete-representational-abstract (CRA) sequencing: beginning with dual balance scale demonstrations, moving to place value charts showing three-column digit shifts, and reinforcing with bidirectional $\times 1,000$ and $\div 1,000$ arithmetic mastery.

Converting Between Grams and Kilograms

Changing Kilograms to Grams

Changing Grams to Kilograms