The factory needs to make 80 ventilation pipes with a length of 2m and a square mouth with a side length of 4dm. How many square meters of iron sheets are needed?
工厂要制作80根长2m，管口是边长4dm正方形的通风管，需要铁皮多少平方米？
<gadget id="calculator">4 / 10</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">80 / 10</gadget>
<output>8</output>

<gadget id="calculator">(2/5) * 4 * 2 * 8</gadget>
<output>128/5 = around 25.6</output>

<result>128/5 = around 25.6</result>