Use iron sheets to make five cylindrical ventilation pipes, each section is 80 centimeters long, and the circumference of the bottom surface is 63 centimeters. How many square decimeters of iron sheets are needed at least?
用铁皮制作圆柱形通风管5节，每节长80厘米，底面的周长是63厘米，至少要铁皮多少平方分米？
<gadget id="calculator">80 / 10</gadget>
<output>8</output>

<gadget id="calculator">63 / 10</gadget>
<output>63/10 = around 6.3</output>

<gadget id="calculator">8 * (63/10) * 5</gadget>
<output>252</output>

<result>252</result>