There is a 60-meter-long aisle in the school, and it is planned to plant trees on the side of the aisle. Plant a tree every 3 meters. If trees are planted at both ends, how many saplings are needed in total?
学校有一条长60米的过道，计划在过道一边栽树．每隔3米栽一棵．如果两端都栽树，共需多少棵树苗．
<gadget id="calculator">60 / 3</gadget>
<output>20</output>

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

<result>21</result>