A cylindrical piece of wood with a base diameter of 10dm and a height of 25dm is sawn into two equal pieces along the diameter, find the surface area of each piece after cutting.
一根圆柱形木料，底面直径10dm，高25dm，沿着直径锯成相等的两块，求切开后每块的表面积．
<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25</gadget>
<output>78.5</output>

<gadget id="calculator">25 / 2</gadget>
<output>25/2 = around 12.5</output>

<gadget id="calculator">3.14 * 10 * (25/2)</gadget>
<output>392.5</output>

<gadget id="calculator">25 * 10</gadget>
<output>250</output>

<gadget id="calculator">78.5 + 392.5 + 250</gadget>
<output>721</output>

<result>721</result>