After folding a rope in half, measure its length (2/5) decimeters. What is the length of the rope in decimeters?
把一根绳子对折后，量得长(2/5)分米，这根绳子原来长多少分米．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

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

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