The volume of a cylindrical oil drum is 251.2L, and the radius of the bottom surface is 4dm, so how many square decimeters of iron sheet are needed at least to make this oil drum (including the oil drum cover)?
一个圆柱形油桶的容积是251.2L，底面半径是4dm，那么做这个油桶(含油桶盖)至少需要铁皮多少平方分米？
<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 16</gadget>
<output>50.24</output>

<gadget id="calculator">251.2 / 50.24</gadget>
<output>5</output>

<gadget id="calculator">3.14 * 8 * 5</gadget>
<output>125.6</output>

<gadget id="calculator">3.14 * 16 * 2</gadget>
<output>100.48</output>

<gadget id="calculator">125.6 + 100.48</gadget>
<output>226.08</output>

<result>226.08</result>