From a rectangle with a length of 9 decimeters and a width of 6 decimeters, the largest square is cut off, what is the remaining area in square decimeters?
从一块长9分米，宽6分米的长方形中，剪去一个最大的正方形，剩下的面积是多少平方分米．
<gadget id="calculator">9 - 6</gadget>
<output>3</output>

<gadget id="calculator">6 * 3</gadget>
<output>18</output>

<result>18</result>