10% of an iron wire is used for the first time, and 25% is used for the second time, how much is left?
一根铁丝第一次用去10%，第二次用去25%，还剩多少．
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

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

<gadget id="calculator">1 - (1/10) - (1/4)</gadget>
<output>13/20 = around 0.65</output>

<result>13/20 = around 0.65</result>