A rope is 2 meters long, cut off (4/5), how many meters are left?
一条绳长2米，剪去(4/5)，还剩多少米？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">2 * (4/5)</gadget>
<output>8/5 = around 1.6</output>

<gadget id="calculator">2 - (8/5)</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>