Divide the 5-meter-long iron wire into 7 parts, each part is the full length ((())/(())), how many meters is each part.
把5米长的铁丝平均分成7份，每份是全长的((())/(()))，每份长多少米．
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">1 / (1/7) / 1</gadget>
<output>7</output>

<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<result>5/7 = around 0.714286</result>