The corridor of a dormitory is 15 meters long and has 6 colorful flags. According to this calculation, the corridor of the office building is 27 meters long, how many colored flags should be planted?
一座宿舍的走廊长15米，插有6面彩旗．照这样计算，办公大楼走廊长27米，要插多少面彩旗？
<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<gadget id="calculator">15 / 5</gadget>
<output>3</output>

<gadget id="calculator">27 / 3</gadget>
<output>9</output>

<gadget id="calculator">9 + 1</gadget>
<output>10</output>

<result>10</result>