Star Elementary School has a playground that is 280 meters long and 50 meters wide. Later, after the school was expanded, the length increased by 20 meters and the width increased by 15 meters. How many square meters has the current area increased compared to before the expansion?
明星小学有一块长280米，宽50米的操场，后来学校扩建后，长增加了20米，宽增加了15米．现在的面积比扩建前增加了多少平方米？
<gadget id="calculator">300 * 65</gadget>
<output>19_500</output>

<gadget id="calculator">19_500 - 14_000</gadget>
<output>5_500</output>

<result>5_500</result>