There is a rectangular fish pond with a length of 52 meters. In order to expand the water surface, the length has been increased by 8 meters, and the area has increased by 320 square meters. What was the original area of the fish pond?
有一个长方形鱼池的长是52米，为了扩大水面，现在又把长增加了8米，面积就增加了320平方米．这个鱼池原来的面积是多少？
<gadget id="calculator">320 / 8</gadget>
<output>40</output>

<gadget id="calculator">52 * 40</gadget>
<output>2_080</output>

<result>2_080</result>