10 cylindrical wooden posts with a base diameter of 8dm and a height of 5dm are to be painted. If it costs 3.5 yuan to paint 1m**2, how much does it cost to paint these wooden columns?
要油漆10根底面直径为8dm，高为5dm的圆柱体木柱．如果每油漆1m**2要花3.5元，那么油漆这些木柱需要多少元？
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

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

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

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

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

<gadget id="calculator">226.08 / 100</gadget>
<output>2.2608</output>

<gadget id="calculator">2.2608 * 10 * 3.5</gadget>
<output>79.128</output>

<result>79.128</result>