A highway has been repaired (1/3), exactly 400 meters have been repaired, how many meters are left to be repaired?
修一条公路，已经修了(1/3)，正好修了400米，还有多少米没有修？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">400 / (1/3)</gadget>
<output>1_200</output>

<gadget id="calculator">1_200 - 400</gadget>
<output>800</output>

<result>800</result>