A cylindrical bucket without a lid has a base radius of 4 decimeters and a height of 6 decimeters. How many square decimeters of iron sheet is needed to make this bucket?
一个圆柱形的无盖水桶，底面半径4分米，高6分米．做这个水桶至少需要用多少平方分米的铁皮？
<gadget id="calculator">2 * 3.14 * 4 * 6</gadget>
<output>150.72</output>

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

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

<gadget id="calculator">150.72 + 50.24</gadget>
<output>200.96</output>

<result>200.96</result>