highway is 2400 meters long, and (2/5) of it has been repaired, how many meters are left to be repaired.
一条公路长2400米，已经修了它的(2/5)，还剩多少米没修．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">2_400 * (3/5)</gadget>
<output>1_440</output>

<result>1_440</result>