The school expanded the playground, the length increased from 50 meters to 80 meters, and the width increased by 20 meters from the original 30 meters. How many square meters has the playground area increased?
学校扩建操场，长由原来的50米增加到80米，宽比原来的30米增加了20米．操场的面积增加了多少平方米？
<gadget id="calculator">30 + 20</gadget>
<output>50</output>

<gadget id="calculator">80 * 50</gadget>
<output>4_000</output>

<gadget id="calculator">50 * 30</gadget>
<output>1_500</output>

<gadget id="calculator">4_000 - 1_500</gadget>
<output>2_500</output>

<result>2_500</result>