The students planted trees on one side of the 100-meter path in the whole field, and planted one every 5 meters (both sides should be planted). How many saplings should be planted in total?
同学们在全场100米的小路一边植树，每隔5米栽一颗(两边都要栽)，一共需要栽多少棵树苗？
<gadget id="calculator">100 / 5</gadget>
<output>20</output>

<gadget id="calculator">20 + 1</gadget>
<output>21</output>

<result>21</result>