There is a square lawn with a side length of 40 meters in the park. Now it is going to be expanded into a larger lawn. The side length has increased by 10 meters. How many square meters has the area of the lawn increased from the original?
公园里有一块边长40米的正方形草坪，现在准备把它扩建成更大的草坪，边长增加了10米，草坪的面积比原来增加多少平方米？
<gadget id="calculator">40 + 10</gadget>
<output>50</output>

<gadget id="calculator">50 * 50</gadget>
<output>2_500</output>

<gadget id="calculator">40 * 40</gadget>
<output>1_600</output>

<gadget id="calculator">2_500 - 1_600</gadget>
<output>900</output>

<result>900</result>