To make a cuboid iron chimney with 15 sections, each section is 2.4 meters long, 6 decimeters wide, and 5 decimeters high, how many square meters of iron sheet should be used at least?
要制作15节长方体的铁皮烟囱，每节长2.4米，宽6分米，高5分米，至少要用多少平方米的铁皮？
<gadget id="calculator">6 / 10</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">2.4 * (3/5)</gadget>
<output>1.44</output>

<gadget id="calculator">5 / 10</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">2.4 * (1/2)</gadget>
<output>1.2</output>

<gadget id="calculator">1.44 + 1.2</gadget>
<output>2.64</output>

<gadget id="calculator">2.64 * 2 * 15</gadget>
<output>79.2</output>

<result>79.2</result>