To build a road, when the full length (3/5) is built, it is 500m away from the midpoint of this road, how many meters is the total length of this road?
修一条公路，当修了全长的(3/5)时，离这条路的中点有500m，这条路全长多少m？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(3/5) - (1/2)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">500 / (1/10)</gadget>
<output>5_000</output>

<result>5_000</result>