The distance between the two buildings is 40 meters, and a cedar tree is planted every 4 meters. How many cedar trees can be planted in a straight line? (Trees cannot be planted directly against buildings)
两座楼房之间相距40米，每隔4米栽一棵雪松，一直行共能栽多少棵？(树不能直接贴着楼房栽)
<gadget id="calculator">40 / 4</gadget>
<output>10</output>

<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<result>9</result>