It is measured that the outer diameter of a certain roll of paper (the paper is rolled tightly without gaps) is 8 cm, the inner diameter is 2 cm, and the thickness of each layer of paper is 0.2 mm. What is the total length of the roll of paper in meters? (π takes 3.14)
测得某种卷筒纸(纸卷得很紧，没有空隙)的外直径是8厘米，内直径是2厘米，每层纸的厚度为0.2毫米，这筒纸的总长度是多少米．(π取3.14)
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

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

<gadget id="calculator">3.14 * 16</gadget>
<output>50.24</output>

<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">50.24 - 3.14</gadget>
<output>47.1</output>

<gadget id="calculator">0.2 / 10</gadget>
<output>0.02</output>

<gadget id="calculator">1 * 100</gadget>
<output>100</output>

<gadget id="calculator">47.1 / 0.02 / 100</gadget>
<output>23.55</output>

<result>23.55</result>