A road has already been repaired (2/5), and the full length can be repaired by repairing another 300 meters. How many meters has the road been repaired?
一条公路已经修了它的(2/5)，再修300米，就能修好全长．公路已经修了多少米？
<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">300 / (3/5)</gadget>
<output>500</output>

<result>500</result>