Two buildings are 50 meters apart, and a tree is planted every 5 meters. How many trees should be planted in total?
两栋楼房相距50米，每隔5米栽一棵树，一共要栽多少棵．
<gadget id="calculator">50 / 5</gadget>
<output>10</output>

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

<result>9</result>