A piece of iron wire, Uncle Wang cut off (5/7) of the iron wire in the first time, and cut less (4/7) in the second time than the first time. ())/(())).
一根铁丝，王叔叔第一次剪去了这根铁丝的(5/7)，第二次比第一次少剪去(4/7)，两次一共减去了这根铁丝的((())/(()))．
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

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

<gadget id="calculator">(5/7) - (4/7)</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">(5/7) + (1/7)</gadget>
<output>6/7 = around 0.857143</output>

<result>6/7 = around 0.857143</result>