A cylindrical iron bucket without a cover is 0.3 meters high and 0.2 meters in diameter at the bottom. How many square meters of iron sheet are needed to make 10 such buckets?
一个无盖的圆柱形铁水桶，高是0.3米，底面直径是0.2米，做10个这样的水桶至少要用铁皮多少平方米．
<gadget id="calculator">0.2 / 2</gadget>
<output>0.1</output>

<gadget id="calculator">0.1 ** 2</gadget>
<output>0.01</output>

<gadget id="calculator">3.14 * 0.01</gadget>
<output>0.0314</output>

<gadget id="calculator">3.14 * 0.2 * 0.3</gadget>
<output>0.1884</output>

<gadget id="calculator">0.0314 + 0.1884</gadget>
<output>0.2198</output>

<gadget id="calculator">0.2198 * 10</gadget>
<output>2.198</output>

<result>2.198</result>