The road construction team wants to build a 3,500-meter-long road, and it has been repaired (6/7). How many meters are left to be repaired?
修路队要修一条长3500米的公路，已经修了(6/7)，还剩多少米没修？
<gadget id="calculator">6 / 7</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">1 - (6/7)</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">3_500 * (1/7)</gadget>
<output>500</output>

<result>500</result>