Suppose you have a rectangular towel with an area of 20 square decimeters and a length of 5 decimeters, what is the width of your towel?
假如你有一张长方形毛巾，它的面积是20平方分米，长是5分米，算算你的毛巾的宽是多少呢？
<gadget id="calculator">20 / 5</gadget>
<output>4</output>

<result>4</result>