ribbon is 10 meters long, cut off (1/5) of it for the first time, and (3/5) of it for the second time, what fraction of it is left?
一根丝带长10米，第一次剪去它的(1/5)，第二次剪去它的(3/5)，还剩下它的几分之几？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (1/5) - (3/5)</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>