The students planted trees on both sides of the path with a total length of 100 meters, and planted a tree every 5 meters (both ends must be planted). How many saplings are needed in total?
同学们在全长100米的小路两边植树，每隔5米栽一棵(两端都要栽)．一共需要多少棵树苗？
<gadget id="calculator">100 / 5</gadget>
<output>20</output>

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

<gadget id="calculator">21 * 2</gadget>
<output>42</output>

<result>42</result>