A piece of iron sheet (4/5) square meters, cut off (1/5) of this iron sheet for the first time, and cut off (1/4) of this iron sheet for the second time, leaving a fraction of this iron sheet Several?
一张铁皮(4/5)平方米，第一次剪去这块铁皮的(1/5)，第二次剪去这块铁皮的(1/4)，还剩这块铁皮的几分之几？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">1 - (1/5) - (1/4)</gadget>
<output>11/20 = around 0.55</output>

<result>11/20 = around 0.55</result>