Students plant trees on one side of a 100-meter-long path, and plant one tree every 5 meters (both ends must be planted). How many saplings are needed in total?
同学们在长100米的小路一边植树，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>

<result>21</result>