-A rectangle of 25dm**2, if its length is doubled and its width remains unchanged, what is its area in dm**2?
-个25dm**2的长方形，如果它的长扩大到原来的2倍，宽不变，面积是多少dm**2．
<gadget id="calculator">25 * 2</gadget>
<output>50</output>

<result>50</result>