Cut an iron wire into two sections, the first section is (4/5) meters long, and the second section accounts for (4/5) of the total length, what is the length of this iron wire in meters?
把一根铁丝剪成两段，第一段长(4/5)米，第二段占全长的(4/5)，这根铁丝长多少米．
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(4/5) / (1/5)</gadget>
<output>4</output>

<result>4</result>