A rectangular test field is 120 meters long and 80 meters wide. If the length and width are increased by 10 meters, how many square meters will the area of the test field increase?
一块长方形试验田，长120米，宽80米，如果长和宽都增加10米，这块试验田的面积增加多少平方米？
<gadget id="calculator">130 * 90</gadget>
<output>11_700</output>

<gadget id="calculator">120 * 80</gadget>
<output>9_600</output>

<gadget id="calculator">11_700 - 9_600</gadget>
<output>2_100</output>

<result>2_100</result>