A rectangular playground is 40 meters long and 25 meters wide. After the expansion, the length increased by 15 meters and the width increased by 5 meters. How many square meters is the current playground area larger than before?
一个长方形的操场，长40米，宽25米．扩建后长增加了15米，宽增加了5米．现在的操场面积比原来多了多少平方米？
<gadget id="calculator">40 + 15</gadget>
<output>55</output>

<gadget id="calculator">25 + 5</gadget>
<output>30</output>

<gadget id="calculator">55 * 30</gadget>
<output>1_650</output>

<gadget id="calculator">40 * 25</gadget>
<output>1_000</output>

<gadget id="calculator">1_650 - 1_000</gadget>
<output>650</output>

<result>650</result>