There is a circular flower bed with a diameter of 20 meters on the side of the Yancheng section of "Ningjingyan Expressway". In order to welcome the Beijing Olympic Games, it is now going to be expanded into a circular flower bed with a diameter of 30 meters. How many square meters will the floor space of this flower bed increase?
"宁靖盐高速"盐城段路边有一座直径20米的圆形花坛．为了迎接北京奥运会，现在要将它扩建成直径为30米的圆形花坛．这座花坛的占地面积将增加多少平方米？
<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<gadget id="calculator">15 ** 2</gadget>
<output>225</output>

<gadget id="calculator">3.14 * 225</gadget>
<output>706.5</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">3.14 * 100</gadget>
<output>314</output>

<gadget id="calculator">706.5 - 314</gadget>
<output>392.5</output>

<result>392.5</result>