The perimeter of a square is 2 decimeters, what is the side length in centimeters?
一个正方形的周长是2分米，边长是多少厘米．
<gadget id="calculator">2 * 10</gadget>
<output>20</output>

<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<result>5</result>