A road is 800 meters long. Trees are to be planted on both sides of the road. One tree is planted every 10 meters, and both ends are planted. How many trees can be planted in total?
一条马路长800米，要在它的两侧栽树，每隔10米栽一棵树，两端都要栽，一共可以栽多少棵．
<gadget id="calculator">800 / 20</gadget>
<output>40</output>

<gadget id="calculator">40 + 1</gadget>
<output>41</output>

<gadget id="calculator">41 * 2</gadget>
<output>82</output>

<result>82</result>