cylindrical gasoline barrel, the radius of the bottom surface is 2 decimeters, and the height is 5 decimeters. How many square meters of iron sheet are needed to make this barrel?
一个圆柱形汽油桶，底面半径是2分米，高是5分米，做这个桶至少要多少平方米铁皮？
<gadget id="calculator">2 * 3.14 * 2 * 5</gadget>
<output>62.8</output>

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

<gadget id="calculator">3.14 * 4 * 2</gadget>
<output>25.12</output>

<gadget id="calculator">62.8 + 25.12</gadget>
<output>87.92</output>

<gadget id="calculator">87.92 / 100</gadget>
<output>0.8792</output>

<result>0.8792</result>