The length of a rectangular vegetable field is 9 meters and the width is 7 meters. If the length remains the same and the width is increased by 2 meters, how many square decimeters does the area of the vegetable field increase?
一个长方形菜地的长是9米，宽是7米，如果长不变宽增加2米，这块菜地的面积增加了多少平方分米？
<gadget id="calculator">9 * 2</gadget>
<output>18</output>

<result>18</result>