25% of a steel pipe is used up, and exactly (6/7) meters are used up. How many meters are left in this steel pipe?
一根钢管，用去25%，正好用去(6/7)米，这根钢管还剩多少米？
<gadget id="calculator">6 / 7</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(6/7) / (1/4)</gadget>
<output>24/7 = around 3.428571</output>

<gadget id="calculator">(24/7) - (6/7)</gadget>
<output>18/7 = around 2.571429</output>

<result>18/7 = around 2.571429</result>