A piece of iron wire is 80 meters long, if (1/4) is used up, how many meters are left?
一根铁丝长80米，用去(1/4)，还剩多少米？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">80 * (3/4)</gadget>
<output>60</output>

<result>60</result>