A road is 400 meters long, and a Metasequoia tree is planted every 40 meters on both sides of the road. How many Metasequoia trees need to be planted in total?
一条路长400米，在路的两侧每隔40米种植一棵水杉树，一共需要种植水杉树多少棵．
<gadget id="calculator">400 / 40</gadget>
<output>10</output>

<gadget id="calculator">10 + 1</gadget>
<output>11</output>

<gadget id="calculator">11 * 2</gadget>
<output>22</output>

<result>22</result>