After folding a strip of paper in half once, the measured length is (2/5) decimeters. What is the original length of this strip of decimeters?
把一张纸条对折一次后，量得长是(2/5)分米，这张纸条原来长是多少分米．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(2/5) / (1/2)</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>