A piece of iron wire is 8 meters long, and 25% of it is used up, how many meters are left?
一根铁丝长8米，用去了25%，还剩多少米．
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">8 * (1/4)</gadget>
<output>2</output>

<gadget id="calculator">8 - 2</gadget>
<output>6</output>

<result>6</result>