A circular pool has a diameter of 400 meters, and trees are planted at intervals of 4 meters along the edge of the pool. How many trees can be planted in total?
一个圆形水池，直径400米，沿池边隔4米栽一棵树，一共能栽多少棵树．
<gadget id="calculator">400 / 4</gadget>
<output>100</output>

<gadget id="calculator">3.14 * 100</gadget>
<output>314</output>

<result>314</result>