To make a 12-section cuboid iron chimney, each section is 2 meters long, 4 decimeters wide, and 3 decimeters high, how many square meters of iron sheet should be used at least?
要制作12节长方体的铁皮烟囱，每节长2米，宽4分米，高3分米，至少要用多少平方米的铁皮？
<gadget id="calculator">2 * 10 * 4</gadget>
<output>80</output>

<gadget id="calculator">2 * 10 * 3</gadget>
<output>60</output>

<gadget id="calculator">80 + 60</gadget>
<output>140</output>

<gadget id="calculator">12 / 100</gadget>
<output>3/25 = around 0.12</output>

<gadget id="calculator">140 * 2 * (3/25)</gadget>
<output>168/5 = around 33.6</output>

<result>168/5 = around 33.6</result>