The construction team repaired a section of road, and when the full length (4/7) was repaired, it had already exceeded the midpoint of 320 kilometers. How long is this road in kilometers?
工程队修一段公路，当修完全长的(4/7)，已经超过中点320千米．这段公路全长多少千米？
<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

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

<gadget id="calculator">(4/7) - (1/2)</gadget>
<output>1/14 = around 0.071429</output>

<gadget id="calculator">320 / (1/14)</gadget>
<output>4_480</output>

<result>4_480</result>