There is a kind of aquatic plant that doubles its growth every day, and grows to 36 square meters on the 18th day, so how many square meters will it grow to on the 16th day?
有一种水草每天长前一天的一倍，到18天时长到36平方米，那么第16天时长到多少平方米．
<gadget id="calculator">36 / 2 / 2</gadget>
<output>9</output>

<result>9</result>