The Nanjing Olympic Sports Center covers an area of about 89.6 hectares, which is 2.1 hectares more than 25 times that of Wutaishan Gymnasium. What is the approximate area of Wutaishan Gymnasium?
南京奥体中心的占地面积约为89.6公顷，比五台山体育馆占地面积的25倍还多2.1公顷．五台山体育馆的占地面积大约是多少？
<gadget id="calculator">89.6 - 2.1</gadget>
<output>87.5</output>

<gadget id="calculator">87.5 / 25</gadget>
<output>3.5</output>

<result>3.5</result>