The "Bird's Nest" covers an area of about 20 hectares, and how many "Bird's Nests" cover an area of 1 square kilometer.
"鸟巢"的占地面积约为20公顷，多少个"鸟巢"的占地面积为1平方千米．
<gadget id="calculator">100 / 20</gadget>
<output>5</output>

<gadget id="calculator">1 * 5</gadget>
<output>5</output>

<result>5</result>