Hope Primary School used to have a rectangular playground, 50 meters long and 40 meters wide. When expanding the campus, the length of the playground increased by 10 meters and the width increased by 5 meters. How many square meters has the playground area increased? ．
希望小学原来有一个长方形操场，长50米，宽40米．扩建校园时，操场的长增加了10米，宽增加了5米．操场的面积增加了多少平方米？．
<gadget id="calculator">50 + 10</gadget>
<output>60</output>

<gadget id="calculator">40 + 5</gadget>
<output>45</output>

<gadget id="calculator">60 * 45</gadget>
<output>2_700</output>

<gadget id="calculator">50 * 40</gadget>
<output>2_000</output>

<gadget id="calculator">2_700 - 2_000</gadget>
<output>700</output>

<result>700</result>