The length of a room is 7 meters, the width is 4.5 meters, and the height is 3.5 meters. To lay tiles below 2 meters on the floor and walls of this room (excluding the area of 2 square meters under the door), how many square meters of tiles need to be laid?
一个房间的长是7米，宽是4.5米，高是3.5米．要在这个房间的地面和四壁2米以下的地方铺上瓷砖(除去门下部的面积2平方米)，需要铺瓷砖的面积为多少平方米？
<gadget id="calculator">7 * 3.5</gadget>
<output>24.5</output>

<gadget id="calculator">7 * 2</gadget>
<output>14</output>

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

<gadget id="calculator">14 + 9</gadget>
<output>23</output>

<gadget id="calculator">23 * 2</gadget>
<output>46</output>

<gadget id="calculator">24.5 + 46</gadget>
<output>70.5</output>

<gadget id="calculator">70.5 - 2</gadget>
<output>68.5</output>

<result>68.5</result>