Process a cuboid tin chimney, its length is 2dm, width is 1.5dm, and height is 2.8m. At least how many square decimeters of iron sheet is needed?
加工一节长方体铁皮烟囱，它的长2dm、宽1.5dm、高2.8m．至少需要用多少平方分米的铁皮？
<gadget id="calculator">2.8 * 10</gadget>
<output>28</output>

<gadget id="calculator">2 * 28</gadget>
<output>56</output>

<gadget id="calculator">1.5 * 28</gadget>
<output>42</output>

<gadget id="calculator">56 + 42</gadget>
<output>98</output>

<gadget id="calculator">98 * 2</gadget>
<output>196</output>

<result>196</result>