Make 10 sections of cylindrical ventilation pipes with white iron sheets, each section is 0.8 meters long, and the radius of the bottom circle is 10 cm. How many square decimeters of white iron sheets are needed at least?
用白铁皮制作圆柱形通风管道10节，每节长0.8米，底面圆的半径是10厘米，这样至少需要白铁皮多少平方分米？
<gadget id="calculator">10 / 10</gadget>
<output>1</output>

<gadget id="calculator">2 * 3.14 * 1 * 0.8 * 10</gadget>
<output>50.24</output>

<gadget id="calculator">50.24 * 10</gadget>
<output>502.4</output>

<result>502.4</result>