20 children of about the same height join hands to form the largest square, and later add 4 children to join in and continue to form a square, so how much will the area of the enclosed square increase at most (fill in the fraction)
20个高度差不多的小朋友手拉手围成一个最大的正方形，后来又加入了4个小朋友加入继续围成正方形，那么围成的正方形的面积最多增加多少(填分数)
<gadget id="calculator">6 * 6</gadget>
<output>36</output>

<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<gadget id="calculator">36 - 25</gadget>
<output>11</output>

<gadget id="calculator">11 / 36</gadget>
<output>11/36 = around 0.305556</output>

<result>11/36 = around 0.305556</result>