There used to be a rectangular lawn with a width of 12 meters in a community. Now increase the width of the grass by 8 meters. The length remains unchanged. This increases the area of the grass by 480 square meters. What is the area of the original grass in square meters?
某小区原来有一块长方形草地，宽12米．现在要将这块草地的宽增加8米．长不变．这样草地的面积就增加了480平方米．原来草地的面积是多少平方米？
<gadget id="calculator">480 / 8</gadget>
<output>60</output>

<gadget id="calculator">60 * 12</gadget>
<output>720</output>

<result>720</result>