A rope is 5 meters long, first use up (4/5) and then use up (3/4) meters, how many meters are left?
一根绳子长5米，先用去(4/5)，再用去(3/4)米，还剩多少米？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">5 * (4/5)</gadget>
<output>4</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">5 - 4 - (3/4)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>