A ruler is 2 decimeters long, how many times do you need to measure a piece of wool 2 meters long with this ruler?
一把尺子长2分米，用这把尺去量一条2米长的绒线，需要量多少次．
<gadget id="calculator">2 * 10</gadget>
<output>20</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<result>10</result>