Students plant trees on both sides of a 40-meter-long path, and plant one tree every 5 meters (both ends should be planted). How many saplings are needed in total?
同学们在一条长40米的小路两边植树，每隔5米栽一棵(两端要栽)，一共需要多少棵树苗．
<gadget id="calculator">40 / 5</gadget>
<output>8</output>

<gadget id="calculator">8 + 1</gadget>
<output>9</output>

<gadget id="calculator">9 * 2</gadget>
<output>18</output>

<result>18</result>