Practice exercises CHAPTER 5 255
<td>
<button id="btnClear">C</button>
</td>
</tr>
<tr>
<td>
<button id="btn7">7</button></td>
<td>
<button id="btn8">8</button></td>
<td>
<button id="btn9">9</button></td>
<td>
<button id="btnPlus">+</button>
</td>
</tr>
<tr>
<td>
<button id="btn4">4</button>
</td>
<td>
<button id="btn5">5</button>
</td>
<td>
<button id="btn6">6</button>
</td>
<td>
<button id="btnMinus">-</button>
</td>
</tr><tr>
<td>
<button id="btn1">1</button>
</td>
<td>
<button id="btn2">2</button>
</td>
<td>
<button id="btn3">3</button>
</td>
<td></td>
</tr><tr>
<td></td>
<td>
<button id="btn0">0</button>
</td>
<td></td>
<td></td>
</tr>
</table>
</div>
</div>