The length of a rope folded in half and then folded in half is 10 decimeters, what is the total length of the rope in decimeters?
一根绳子对折再对折的长度是10分米，这根绳子的总长度是多少分米．
<gadget id="calculator">10 * 4</gadget>
<output>40</output>

<result>40</result>