A 20 decimeter long iron wire surrounds a square, what is the side length of this square in centimeters?
用一根20分米长的铁丝围成一个正方形，这个正方形的边长是多少厘米？
<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<gadget id="calculator">5 * 10</gadget>
<output>50</output>

<result>50</result>