The window of the classroom is 25 decimeters long and 20 decimeters wide, what is its area in square meters?
教室的窗户长25分米，宽20分米，它的面积是多少平方米．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">25 * (1/5)</gadget>
<output>5</output>

<result>5</result>