large pond is gradually covered by growing plants, and the newly added coverage area doubles every day. On the 9th day, half of the pond is covered. How many days does it take for the large pond to be completely covered?
一个大池塘被正在生长的植物逐渐覆盖，每天新增的覆盖面积加倍，第9天池塘已被覆盖一半，那么大池塘全部被覆盖所需的天数是多少天
<gadget id="calculator">9 + 1</gadget>
<output>10</output>

<result>10</result>