A piece of cylindrical wood with a length of 10 decimeters and a diameter of 2 centimeters, if it is cut into how many pieces, the surface area will increase by 25.12cm**2.
一段长10分米的圆柱形木料，直径为2厘米，如果把它截成多少段，表面积就增加25.12cm**2．
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1</gadget>
<output>3.14</output>

<gadget id="calculator">25.12 / 3.14</gadget>
<output>8</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<result>5</result>