There is a road 800 meters long, and a poplar tree is planted every 20 meters from the beginning to the end of the road. How many poplar saplings are needed?
有一条长800米的公路，在公路的一侧从头到尾每隔20米栽一棵杨树，需多少棵杨树苗．
<gadget id="calculator">800 / 20</gadget>
<output>40</output>

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

<result>41</result>