Make a pair of cylindrical open buckets. If its base radius and height are both 10 decimeters, how many square meters of iron sheet are needed at least?
做一对圆柱形的无盖水桶．如果它的底面半径和高都是10分米，那么至少需要用多少平方米的铁皮？
<gadget id="calculator">2 * 3.14 * 10 * 10</gadget>
<output>628</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">3.14 * 100</gadget>
<output>314</output>

<gadget id="calculator">628 + 314</gadget>
<output>942</output>

<gadget id="calculator">942 / 100</gadget>
<output>471/50 = around 9.42</output>

<result>471/50 = around 9.42</result>