Make a cylindrical tin bucket without a lid, the diameter of the bottom is 4 decimeters, and the height is 5 decimeters. How many square decimeters of iron sheet are needed to make 5 such iron sheet buckets?
制作一个无盖圆柱形铁皮水桶，底面直径是4分米，高是5分米．做5个这样的铁皮水桶，需要铁皮多少平方分米？
<gadget id="calculator">3.14 * 4 * 5</gadget>
<output>62.8</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4</gadget>
<output>12.56</output>

<gadget id="calculator">62.8 + 12.56</gadget>
<output>75.36</output>

<gadget id="calculator">75.36 * 5</gadget>
<output>376.8</output>

<result>376.8</result>