A rectangular parallelepiped water pipe has a length of 40 decimeters, a width of 2 decimeters and a height of 1.5 decimeters. How many square meters of iron sheets are needed to make a section of such a water pipe?
一种长方体流水管，每节长为40分米，宽2分米，高1.5分米，制作一节这样的流水管至少需要铁皮多少平方米？
<gadget id="calculator">40 * 2</gadget>
<output>80</output>

<gadget id="calculator">40 * 1.5</gadget>
<output>60</output>

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

<gadget id="calculator">2 / 100</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">140 * (1/50)</gadget>
<output>14/5 = around 2.8</output>

<result>14/5 = around 2.8</result>