A wooden pole, cut off the full length (1/2) for the first time, cut off the remaining wooden pole (1/3) for the second time, and cut off the remaining wooden pole (1/4) for the third time , cut off (1/5) of the remaining wooden pole for the fourth time, and at this time, the length of the remaining wooden pole was measured to be 6 cm. What is the original length of the wooden pole?
一个木杆，第一次截去了全长的(1/2)，第二次截去所剩木杆的(1/3)，第三次截去所剩木杆的(1/4)，第四次截去所剩木杆的(1/5)，这时量得所剩木杆长为6厘米．木杆原来的长是多少厘米？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">6 / (4/5) / (3/4) / (2/3) / (1/2)</gadget>
<output>30</output>

<result>30</result>