The school used to have a square flower bed with a side length of 4 meters. Now it has been expanded to a side length of 5 meters. How much has the area increased?
学校原来有一个边长是4米的正方形花坛，现在扩建成边长为5米，面积增加了百分之几？
<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">25 - 16</gadget>
<output>9</output>

<gadget id="calculator">9 / 16</gadget>
<output>9/16 = around 0.5625</output>

<result>9/16 = around 0.5625</result>