A steel bar is cut off by 20% and then connected to another 2 meters. At this time, the steel bar is shorter (1/10) than the original one. How long is the original steel bar?
一根钢筋，锯下20%后，又接上2米，这时钢筋比原来短(1/10)，原来这根钢筋有多长？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/5) - (1/10)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">2 / (1/10)</gadget>
<output>20</output>

<result>20</result>