Plant trees on the side of a 240-meter-long road, plant them from beginning to end, and plant a tree every 15 meters. How many trees do you need in total?
在一条长240米的道路一旁栽树，从头到尾地栽，第隔15米栽一棵．一共需要栽多少棵？
<gadget id="calculator">240 / 15</gadget>
<output>16</output>

<gadget id="calculator">16 + 1</gadget>
<output>17</output>

<result>17</result>