The house numbers on the same side of the road are generally consecutive odd numbers or consecutive even numbers. The sum of the house numbers of 10 consecutive houses on the same side of a certain road is 540. Then, what is the house with the smallest number.
马路同一边的门牌号码一般是连续的奇数或连续的偶数，某条马路同一边连续10户人家的门牌号码之和是540，那么，号码最小的那家是多少号．
<gadget id="calculator">2 + 18</gadget>
<output>20</output>

<gadget id="calculator">9 / 2</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">20 * (9/2)</gadget>
<output>90</output>

<gadget id="calculator">540 - 90</gadget>
<output>450</output>

<gadget id="calculator">450 / 10</gadget>
<output>45</output>

<result>45</result>