A road has been repaired for 300 meters, and the full length (2/5) has been repaired. How many meters are left?
一条路，修了300米，修了全长的(2/5)，还剩多少米？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">300 / (2/5)</gadget>
<output>750</output>

<gadget id="calculator">750 - 300</gadget>
<output>450</output>

<result>450</result>