There is a 400-meter-long embankment with trees planted on both sides (both ends need to be planted), and one tree is planted every 5 meters. How many trees should be planted in total?
有一段长400米的堤岸两边栽树(两端要栽)，每隔5米栽一棵，一共要栽多少棵．
<gadget id="calculator">400 / 5</gadget>
<output>80</output>

<gadget id="calculator">80 + 1</gadget>
<output>81</output>

<gadget id="calculator">81 * 2</gadget>
<output>162</output>

<result>162</result>