After (2/3) of a steel pipe is used up, there are 5 meters left. How long is the steel pipe originally?
一根钢管用去(2/3)后，还剩5米．这根钢管原来长多少米．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">5 / (1/3)</gadget>
<output>15</output>

<result>15</result>