Xiaoduo travels from A to B, among which (2/7) is an uphill road, (4/7) is a flat road, and the rest is a downhill road, a total of (3/8) kilometers downhill, Xiaoduo is from A to B How many kilometers did you walk in total?
小朵从甲地到乙地，其中(2/7)是上坡路，(4/7)是平坦路，其余是下坡路，共走下坡路(3/8)千米，小朵从甲地到乙地共走了多少千米？
<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">1 - (2/7) - (4/7)</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">(2/7) + (1/7)</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">(3/8) / (3/7)</gadget>
<output>7/8 = around 0.875</output>

<result>7/8 = around 0.875</result>